1. It depends on what Bob wants. If Bob wants to occasionally dress as a man, fine. If it means wearing mens boxers and t-shirts under her clothes, dressing at home, occassionaly going out as a male, being somewhat androgynous I'm all good. If Bob wants to take hormones and lie life as a male, I'm not too certain about that, just as I don't think my wife would stay with me if I wanted to transition. Given my cross dressing perspective though, I might at least give it a try.
2. Pretty much the same I would expect, a lot less than I actually get
3. Not sure how it would change the relationship. I think it would allow be to be a little more submissive, which I kind of lean towards anyway.