Maybe it's just semantics, but would the wording "make a roll to create or gain access to an aspect" be important?  When taking a consequence to super charge a spell you never actually roll anything to create said consequence, possibly implying "no roll = no free tag".

Actually, that's a good way to do it.  You make them roll right before the scene in which they're going to be casting.  Whatever shifts don't get used at the end of the scene go away.

Because people like custom powers?

Edit: 

I'm in the scene aspect/compel boat on this one, but...

Here's a question:
To reiterate sanctaphrax's comment:  what prevents you from calling up 100shifts.

On that same line of thinking, where do you draw the line for the number of naval-gazing maneuvers one can do before a big fight?

I would raise the difficulty of the roll for every declairation.  Representing it getting more and more difficult to hold the power drawn, and not allow further attempts after the first failed roll.

Also that the player is throwing a different aspect on themselves every time they roll.  It becomes very very easy to compel them multiple times.  Like say losing control of some or all of that power at the worst possible moment.  It would cost them a lot of fate points to buy out of it if they went overboard on the aspects.   

I know this is based off very limited information, but it seems like your GM ignored basic core game mechanics to railroad the story in the direction he wanted.  It seems you threw him off his story planning.  Despite this it sounds like he is continuing to ignore mechanics, or rather flat out not allow them, to push his own story agenda.  There's many many game mechanics he could of used to prevent your current impass, a simple compel may have been able to avoid the entire thing.  But for some reason chose not to employ any of them.

Your GM needs to either A. Start adjusting his story based on what you as players are doing instead of disallowing mechanics whenever it suits him.  Or B. Be very transparant regarding the situation.  By that I mean if he really needs the NPC alive, he needs to tell all of you that and ask that you work with him on this.

IT'S possible, but as already pointed out, it's a bit redundant unless the effect was specifically made with extension in mind.   As you're still using an action and a charge to do the exact same thing.

I wouldn't allow it for enchanted items personally.  One reason being if the RAW doesn't explicitly say you can do it, my answer is "no you can't do it" 9 times out of 10.  Themeatically, enchanted items are pre-packaged spells that are charged up ahead of time.  Also I wouldn't allow it because enchanted items don't just mimic evocation.  They can also replicate Thaumaturgy.  You could get around almost all the Thaum limititations if it were allowed.

Extending Rotes however falls into the 1/10 for me.  Rotes still count as evocation and still follow all the same rote rules and applications once cast as far as I'm concerned.

Nothing wrong with players compelling eachother.  It fits the co-op storytelling style of Fate.  Just remember all compels still need GM approval.  If your players are regularly sitting on 10+ fate points, I would suggest throwing more situations that force them to use FP and/or giving the compels more teeth.  Your players will be less eager to go compel crazy if they know they are going to really suffer for their FP's.

@Mrmdubois:
I would play them as pyshomantic wards myself where as Harry's mental defense against Corpstaker in Dead Beat was a pyschomantic block evocation.

@JDK002:
Did you play it like the fatigue belt in Fool Moon? All it did was TEMPORARILY clear the track and then...all of a sudden...Harry was hammered again. I'd say that'd be a fair way of getting a little more mileage out of a potion like that (and ones casting) while not breaking the game.

not initially, though when we start playing again I'll probably do something like that.  Power of the potion = number of exchanges it lasts for.  Being able to cast up to your conviction without taking mental stress.  But when it wears off the stress track fills and maybe have to take a mild consequence if you don't have one already.

Okay I just attempted to do a write-up of The Doctor at Submerged and scrapped the whole thing.  Even at that level as a PC he suffers a massive power-down, particularly with stats.  Trying to properly stat block him with 35 skill points and keep true to the character seems like it will just turn him into a rather ho-hum techno oriented detective who's powers don't really facilitate much difinitive mechanical bonuses.