1) No idea; personally I think they must be masochists to even consider a Prince Albert. For nipple piercings, same reason some get their tongue pierced.
2) Yes; there was a guy in my HS who had a piercing on his left nipple(will get back to him).
3) Yes; especially a Prince Albert; I imagine that men who get one have issues when nature calls....
Now back to that guy in HS.....
He had 8 or so piercings on his face: lip, nose, ear and eyebrow(with like 4 or 5 up here). He then had a gold chain connecting his nose to his eyebrow, and his eyebrow to his left ear; the whole effect was grotesque.
Then when we were in 10th grade, gym class, touch football, and of course people didn't just "touch"... He got tackled, someone's foot got too close, and the rest is pretty bloody. Tore his face apart completely; nose had a huge hole in it, his eyebrow was just GONE, and a chunk from the top of his ear.
And this is why I will never get any piercings done....one exception is a stud in my earlobe(which someone will have to talk me into), but that's it.