1. It's not so much the flares that are the big problem, it's the tire rub on the inside of the fenders that are the problem, but trimming flares would help if you had more backspacing on your wheels
2. With a 2 inch BB, you can run 32 safely (might vary for wheel choice), don't know exactly how much of a difference the flares would make, because of #1
3. No Idea, I've never done it.