but it's better than FF10 and I need to play something to keep me motivated/enraged enough to finish making my own game.
Yeah, I thought almost the exact same thing last time I played FF12. (the difference being that I never played FF10, so I played through FF12 to make sure I wasn't curious enough to make the mistake of ever playing FF10) I can only speak for personal experience, but despite thinking it would help motivate me to work on my own games, that did not work out at all.
The way I see it, I don't think there is a single final fantasy game that won't do anything but distract you from making games. But if you want to try for it anyways, your best chance is to try tricking a friend into playing FF13 while you sit in the same room watching him do it.
If you are next to your computer, or next to anything really, you cannot help but find any way imaginable to distract yourself from watching your friend play FF13. Any time you do look at the person playing FF13, you will be so pissed off you will eventually force yourself to make a better game, since it would be stupid easy for anyone to do given how awful that game is. (Also, the best part of it is no matter how little actual progress you get in making that game of yours, it will feel like more of an accomplishment than ANYTHING your friend could ever accomplish while playing FF13)