Any sort of major celestial event could be considered a threshold. The dates of the major changes of seasons; the equinoxes and solstices (Midwinter and Midsummer) as well as the cross-quarter days. A new or full moon could be one also.

A Fall Line could be a threshold as well as a ley line so could any sort of large geologic feature like a fault line or the Pacific Ring of Fire. I could also see three or more ley lines crossing in close proximity forming a threshold to the area inside them.

Some historical stuff that would just make everything make more sense.

Two of your plans are just bad ideas in a feudal system. They are how civil wars get startedn not that they arn't happening anyway, but the First Lord would never do what your suggesting as it would just open the realm up to problems.

In a feudal system its not really practical to take land away from a lord and move him. All the underlings are sworn to him and have loyalty to him. Land is granted to a man and all if his descendants for all time. Taking land, even to give him something better is a slap in the face.
 You can't practially move High Lord Riva, a lot of his power comes from the generations his family has built up connections in the area. Promotions are fine, promote the two you were going to put in Riva in Aquitaine, but a High Lord is technically a High Lord.

You can't give Crassus and Maximus both cities unless one of the them is Antillus. One of them has to be the High Lord of Antillus someday. He would end up with with 2 cities making him and his family way to powerful and upsetting the political balance. I havnt read the last book so you may have some reasoning Im not aware of but this just seems like a bad idea.

City dwellers should be Urbanus from the Latin for "city" not Civilus meaning "citizen".


Now the stuff that just my opinion about your rules you can just ignore this:
I think the concept of level based games is a step backwards in roleplaying. As is being more numbers heavy with attributes and skills. Rather than having backgrounds, jobs, magic just give people points and let them build a unique character. Its so frustrating in a game system when the rules say I can only play X with Y powers and never get Z power because it doesn't fit some arbitrary rule. Think how many time you wanted to play a Dwarf Paladin, or a Fighter with just 1 magic spell. Thats the system you seem to be setting up and it doesnt reflect reality or the characters in the book. They arn't limited in growth because someone chose Paganus for Tavi on day 1.

Watch politicians. The good ones never lie. They make vague statements that were true once, but may not be now and speak in the past tense, they avoid answering the question, they put qualifiers around everything.

1. "I have been called X" works. Making a truthful statement about the past is always acceptable. Of course its really douchy to look at a follower and say "Call me Ceaser". He does. Then tell the players "I have been called Ceaser". If you can't answer then say something like "My name isn't important", "I have many names", "You may call me what you wish", "We are in a Church so lets go with Mr. Church". There are so many variations there is no reason for this to be a problem.

2. Is your truthsayer an oracle? They shouldn't be answering questions about the future directly  unless they know the future because if they make any statement about the future that doesn't come to pass they lied. Their answer should be something like "death is always an option", "it is possible you could survive", "it would be safe for me".  Your truthsayer simply can't say that the action will or won't kill the person unless they have knowledge of the future. They can suspect and be pretty sure it will, but something in the universe could make it so that they would be wrong and hence lie.

3. Gramatically the person is lying. Without additional qualifiers when saying the "sky is red" it applies to the present location and time, not some unstated far off place or time. You cant say "the sky in red" and then think in your head "on Venus" and make it count. The person spoke a lie, they spoke and thought the truth.

4. If you directly pulled this crap as described after I punched you in the face I'd leave and never game with you again.  You can speak in code, but you must first notify the listeners you are doing so, and they need a copy of the code or a basis to translate it. They don't have to have read it just had it made available. Now if they miss the line or misunderstand "Admiral, if we go "by the book". like Lieutenant Saavik, hours could seem like days. " that's their fault. But they were told you were speaking in code, and what the code was. Spock is a great example, he does not lie (usually). He might exaggerate the truth, speak in an open code or leave out info but he doesn't just lie which is what you are suggesting.

If you have to resort to #3 or #4 (as you described it, not with the additions I described) its time for you to get rid of the character your not a good manipulator and shouldn't by trying this sort of thing. It will a better game if you play to your strengths as a GM and not try things that end up making the players mad.

when would his spells NOT fit the Lord's will, if he stays in character?

Its only overpowered if he is allowed to run rampant with it.

How does he know its the Lord's will? Is the Lord sending down messengers or giving him signs? The Knights don't just run out and kill things, even evil things. Only certain missions constitute the Lord's will, and using his powers outside those parameters can lead to disaster. Is he giving the opposition a chance to repent first like Michael does quite often?

What happens when the Lord says that evil Black Court Vampire the character wants to fry has to live for some greater purpose? Perhaps the Lord needs the Vampire to enthrall and slaughter a few hundred children as a lesson in how evil the world can be in order to reform just one Denarian. The Lord works in mysterious ways, play it up.

Heck, have some Denarian pretend to be an angel and start giving him false signs and messages from the Lord. That little old lady? She is secretly a demon and needs to be purged. If the player wants to use his soulfire all the time build a scenario where he is going after people who look bad but are really good, situations like where Molly tries to help get people off drugs. Make Molly the "evil" he needs to go after, and once he does let him see the larger evil it causes when he does stop her his way.

Elements wise I'd break it into:
Gravity
Electromagnetism
Entropy
Quantum

I'll post examples tonight if you want

I'd say you really should use the 4 fundamental forces:

Electromagnetism:  Just about every interaction we see in life except gravity including all chemical reactions because they are really interactions between charged particles,

Gravity: interacts with all particles that have mass,  always attracts and never repels, can't be shielded against, absorbed or transformed,  effects large bodies because their charges are effectively neutral other wise electromagnetism is much stronger.

Strong Nuclear Force
  Holds quarks together. the strongest force but very very small range (inside atoms only)

Weak Nuclear Force
   radioactivity beta decay

I have no idea how you would manage to do anything with the last 2 because of the way they work. Obviously the real power would be doing all the things with gravity that you can't do, and electromagnetism. Maybe you could divide those 2 up into more elements and ignore the nuclear forces.

Actually the 7th doesnt' have any leeway.   Knowledge about the outsiders is strictly forbidden.   IN any capacity.  Technically harry is breaking the 7th law simply by knowing HWWB's name.

Did you read the first post?

This thread is dedicated to trying to determine how one can accomplish certain results that would otherwise be possible only through violation of one of the seven Laws of Magic, without actually "staining" your soul.

Knowing HWWB would in no way stain you but could be a violation. The 7ths has lots of leeway you can learn a lot of things about the Outsiders that would get you killed by the Council but wouldn't stain you.

This is only assuming the Judeo-Christian Creator, which is not necessarily the case.

I think Butcher has made it clear the Creator is Judeo-Christian, or least something similar. It has something to do with 3 guys with swords, nails and named archangels. Even if we say the Creator is something vaguer and more broad scoped, no mainstream religion support outright killing and while the wording might not be the same the same basic rule applies in all of them. Some of them allow and even require killing criminals of various kinds but outright murder of innocents is always out, and thats really what he is trying to get away with. Yes, I know fanatics in every religion find a way to justify killing someone they don't like, that doesn't mean it doesn't violate the religions basic tenants.

No, the love potion was explained as grey.

And that's exactly what we are talking about grey areas. Sometimes the Laws might be overly strict, others they might actually be to lenient. IMO love potions would be that too lenient area. They stain slightly but the council can't really condemn every high school girl who makes one, they don't have enough time on their hands. Then the question becomes how effective the potion is anyway? Who can test every case to see if the boy fell in love on his own or some girl actually managed to create a potion?

According to the rules it does.

According to the rules you get lawbreaker for it. And there is a 99.9% overlap between the laws and stain.  I don't think the actual time travel generates a stain, I just think its impossible to go back in time and not mess something up which does cause a stain. Its a fine line, so fine that its impossible to not wreck the natural order when doing it, but the discussion is what can you do without getting a stain. Travel no stain. Do anything once you have traveled, including breath, walk, etc.  stain.

#1: The problem here is that Butcher set up the world with a Creator. With the first law your trying to break his basic rule, "Thou shalt not kill" without consequences. I don't think you can. I'd argue that even when the Wardens kill with a sword it stains their soul, just not in the same way as with magic. The White Council can stop people from killing with magic but not killing without it so they only care about the former, that doesn't mean the latter is any better. Talk to you local religious figure about how you can kill someone and yet not be responsible.

#2: A properly researched, well thought out ritual to transform  a person which takes into account all the consequences for storing their soul/mind/personality and allowing them to transform back at their will probably doesn't stain the soul. Spend a few decades doing the research on that one.

#3: The problem here is "invade". There has been a lot of discussion that if the invasion is voluntary then it might be ok, or if its just looking around. Yea sure, some of those particularly the looking into a voluntary subject might not stain the soul. But its too tempting to do a little tweak while in there, or look at secrets the person has. While in someones head can you resist the temptation to see what they really think of you? Probably not and if you do you just crossed the invasion line. The Council has determined that even defensive mind magic seems to be too close to breaking this law so they don't even teach anything beyond the basics. That seems a bit too far but its so the temptation never exists. To break this one I'd say it has to be 100% voluntary, no coercion, no threats, not even a you need to prove you innocent type of thing, and then only looking and only looking at the specific info they allow. Well if you meet all whose conditions there really isn't a reason to look is there?

#4: Any enthrallment is a stain, this one is clear. You can't make someone do anything, even love potions without negative effects.

#5: The stain only seems to apply to crossing the borders for things with souls. Sue was an abomination, but not a killable offense. Raising an army of zombie bunnies seems to at least tolerated. Again this comes back to the Creator issue. He won't like you bringing back the dead, what Koumari does will noble probably violated the Creator/Universes rules about that.

#6 I don't think the 6th stains the soul at all, its just such a bad idea to go back in time that it has to be stopped. To many actions messing with the past lead to breaking the "thou shalt not kill rule", even if you don't use magic beyond the time travel part. Changing history means someone out there died who didn't before and you were the cause. You could probably go back, veiled, levitating and incorporeal leaving no trace and record events without causing a stain but extreme precautions would need to be taken not to influence anything. Precautions which are probably so difficult as to be impossible.

#7 The 7th has a lot of leeway. Research that never contacts an outsider probably doesn't hurt at all, its just that those who start to research write it down and other people pick up that work with bad consequences.
Dealing with one is just a road to corruption.