There is no rule on how long it takes to activate an enchanted item. Attacking with one or maneuvering with one takes a standard action though.
This is pretty much how I would rule. Using the attack spell on an item counts as one action, you just don't have to pay casting stress or control the spell. Like a ramped up rote, if you will.
I would be careful with letting someone just use maneuver items though. That would be 4 free +2 tags per refresh. Double that (or triple, etc.) if you have any frequency crafting bonuses. That can get messed up real fast. Maybe as a supplemental action, which would mean you would still get +1 for each activated item. Or maybe 1 per exchange. At least some kind of restriction on the use, or things get ugly fast.
On the other hand, I can see a wizard with one of your self sponsored magics, where he stores a lot of energy in items, that he uses on his magic. Would account for the free tag and the debt (needs to make more items) rather nicely, and you wouldn't really need to keep track of how many items you actually got.
On block/armor items, I would let the reactive part stick. Maybe under the restriction, that it only works on that attack, regardless of whether or not it has power dedicated to duration.
1. Remove Rotes from the game.
I wouldn't go so far, but maybe half the power rounded up for rotes. That way you really do trade power for safety. And it may increase the use of maneuver rotes.
2. Increase the Refresh cost of spellcasting powers.
3. Remove the free specializations from Evocation and Thaumaturgy.
4. Reduce the number of free focus slots that spellcasting powers give.
I think the prices are fine as they are. If you want to make wizards rarer, that'd be a good option, but I think they are just in line with the rest of the powers.
5. Make backlash come in the form of consequences rather then stress.
That's a nasty idea, but it might have some merits. It will definitely make the wizard player more careful and maybe leave an inch or two between the maximum power he could throw and what he actually does, to be on the safe side.
6. Put a hard limit on the number of allowable thaumaturgy Declarations.
Remember that it not only requires a skill roll, but time as well. Most of the time, you should be pressed for time, so you will only do the bare minimum and go on. If the players want to pull of a gigantic ritual, then why not make that ritual the center of the campaign?
7. Make elements more restrictive by requiring them to be present in the environment before they can be used.
8. Get rid of the Spirit element.
That would just make everyone take air and earth magic. And our most prominent wizard throws fire around all the time, without it being present.
9. Make elements more restrictive by tying them to specific mechanical actions.
If you do that, you would have to restrict other actions, too. You wouldn't be able to put up a block with guns coverfire) or things like that, which would take out a big part of what makes the FATE system great.
10. Make the difficulty of thaumaturgical control rolls increase with the complexity of the associated ritual.
Care to elaborate? I don't really understand what you mean.
11. Make it so that drawing 2 shifts of power over your base power fills in your first 3 stress boxes rather than your 3rd, and so on.
Again: if you did that, it should work like that for everything. Hunger stress for example, but regular stress as well.
12. Require foci to follow a pyramid structure.
13. Allow only a single focus to be used for each spell.
14. Do not allow Evocation and Thaumaturgy focus slots to be intermixed.
That'd certainly be an option, though I think that would greatly devalue focus items. Every wizard would just take specializations instead, because they would be a whole lot better. And a big part of focus items is the item part, you can take them away from the wizard to cripple him. How are evo and thaum slots mixed?
15. Do not allow people to inflict consequences to fuel Thaumaturgy unless the target is important enough to take those consequences.
Isn't taking consequences a sign that it is important to the character? And consequences can be compelled 6 ways from sunday, especially things like those.
16. Make all Enchanted Items require an action to activate.
17. Make all non-armour Enchanted Items require an action to activate.
See my opening statements.
18. Remove Crafting frequency bonuses from the game.
19. Do not allow Crafting foci.
That might be a wise thing to do. Or maybe change them around a bit. For example, a frequency specialization could grant you a number of extra uses equal to your Lore skill, and you can only add 1 use per frequency specialization to any given item. It would be equal to the current state if you have equal or less enchanted items than your Lore, it would be weaker if you had more. Should be a good middle ground. Or lose it altogether and let wizards buy their uses per session by buying more enchanted item slots, I think I would be fine with that.
20. Make Thaumaturgy less efficient at imitating other skills with a tax or a bad exchange rate.
The bad exchange rate is usually time. And often enough, the result will still be pretty crude, so for some things it just won't be an option (great thing to compel on).
21. Make control bonuses not apply to attack accuracy.
I've seen this debated a lot of times, and I am torn on the subject, to be honest. Maybe give attack spells a fixed power (maybe through specializations in attack, maneuver, block?) and then only roll to target. Would devalue conviction for wizards though, if you don't find another way to put it to use. This would turn all spells into rote spells, but maybe that's something to build on.
You could give wizards the equivalent of a gun, an attack spell that doesn't cost stress to use but is pretty weak. Maybe a weapon:2 spell. Or hell, why not 1 or even 0? It would allow them to cast a lot more spells, but they would hit a lot weaker than regular folks with good weapons. But the bigger guns would cost equally more juice to pull off, so they would still be able to bring on the doom, only not with every spell they throw.
22. Make zone attacks cost more, and/or make them cost both power and control.
That actually makes a lot of sense, given that you would have to take a -2 on something like a machine gun attack, too.
23. Do not allow people to prolong spells with other spells.
Since you can only prolong block spells (Or rather: I wouldn't allow prolonged attacks, and I usually have maneuvers last for the scene anyway), that would be 2 out of 4 pre-consequence spells right out the vent, in a time where the bad guy can put up 2 maneuvers and tag them in the third exchange to easily break through that block. I think it's good as is. Maybe it can become a problem with high powered enchanted items, but that's another case to debate.
24. Do not allow people to redirect spells.
If it's a cool redirect, then why not? The example of Carlos using his entropy cloud to kill that ghoul is just a cool action, so I would strongly encourage the use.
25. Make actual rules for accidental hexing.
A compel should work fine, I think. It happens when it is interesting to the story, otherwise, why bother? Otherwise I feel this could be a lot of dice rolling really fast.