...I don't think Roy can just snap his fingers... He still needs the spark cloth, I would think. He just doesn't need the circle that's on the gloves. So long as he can get that spark.
What I was really confused about was how Al's soul was talking to his body. Is his soul split and part of it's still in the body? Is Truth hanging out in Al's body for these times? Is there something else entirely inhabiting Al's body while the soul is away? How the heck did that scene work?
Knowing me, this is one of those things you're not supposed to notice, but with the evil Al body at the end of that part, there's reason to believe there's something else at work there.
Also, if Al had returned with his body, would he still have been a sacrifice or would the entire thing be null and void (because having an out like that and not knowing it would be awesome and ridiculous).
Guess we'll find out next month. =/