This is kind of a part II to this thread (http://www.indie-rpgs.com/viewtopic.php?t=13178).
Okay. So I did some thinking and some tinkering, and tried to figure out something to create the "gas" effect that Sidney keeps talking about. What I came up with was simply this - every scene that you don't use your powers, you gain a Strain (not totally thought out, but thats the core of the idea). The only way to lose Strain is to get in conflicts (or just give yourself constant -1's). Basically, doing what Sydney said, and making the power of Time Travel dangerous.
Problem is, I don't want it to be dangerous. And this got me to more thinking, and I eventually started thinking about it in terms of CAs, and came to this revelation...this is really a simulationist game. In a big way. And I like that - when I play, I want to bum around and mess with my time travel powers and do all that. I don't want this game to be about Premise. But I can see how some-one who did could drift it more Narrativist, by doing something like the above mechanic.
So I feel like including it in the "alternate settings" area with a little sidebar explaining its purpose and such.
Is that just waffling, though? And am I even on target with my CA ruminations? I dunno. I feel like some thoughts from the smart folks around here would be helpful.