I'm of the opinion that characters probably shouldn't have evothaum, except within the mixed blessing framework of sponsored magic. But for those who do, consider:
1) Custom power creation uses the same baseline guidelines as stunts, but are allowed a bit more punch.
2) Options for stunts include:
Reduce the amount of time necessary to complete a particular task by two steps.
3) Thaumaturgy cast as Evocation would have the same
effective limits on complexity as Evocations do on power, so it's unlikely to see spells that would normally be hours-long rituals be cast this way. For the most part, this capability would cover spells that might otherwise take, say, minutes. Maybe 15 minutes or so at most?
4) Going from "15 minutes" down to "a few moments" (ie, a combat exchange) on the time chart (YS315) is four shifts.
Given the above, it seems to me that the price point for a Power that causes Thaumaturgy to be cast at Evocation's speed is on the order of -2 Refresh (which buys a four shift reduction on the time chart when performing Thaumaturgy, and would be on top of the cost for Thaumaturgy itself). Maybe less (-1 might be too little, though), considering that Thaum at Evo speed doesn't effect much more complex Thaum cast not at Evo speed (ie, you can't cast a ritual that might normally take a week in a few hours). As I said, I wouldn't make such a power available; just going through the logic problem of how such a thing might be costed.
My reading of sponsor debt is that if you spend the FP to resist a debt compel the point of debt that fuelled that compel is still spent. After all, you spent the FP you "borrowed".
Is there some evidence to the contrary somewhere that I missed?
Here:
"When you spend a fate point to resist a sponsor’s debt compel, does your debt still go down?"
"No, it doesn’t. But the sponsor can’t force that same issue again, either. You get to refuse that specific compel. But another one — and granted, a different one — is headed your way later."
