1. Yes, there's no reason that it wouldn't. Cranks don't contact cassettes - as long as they'll both use the same chain (and in this case, they will) and if you have a derailler that can take up enough chain slack (29 teeth's worth, although in practice I think your max range would be 26 teeth's worth), then you're good.
2. Not quite. It gives almost as high of a gear as a typical road triple with 52t chainring, but not as low of a gear as a road triple with 30t small chainring, and certainly not as low as a 110mm bolt-pattern triple with 26 or 24t small ring. But 34*25 is a pretty low gear nonetheless.
3. I don't know.
I'm not sure what sort of riding you do, but if you have long climbs out near Asheville/Boone area, and like to sit while you climb, you might stick with a triple. Here in Chapel Hill, I've got a triple and never touch my granny ring, even up 2/3 mile hills.