Answer:
nope, quite the opposite in fact. it builds stamina and endurance.
No. If anything it will improve your length of time with a partner.
No way. That's just something uptight people tell boys to discourage them from doing it. They used to say it could drive you insane, for the same reason. If that were true, most guys would be crazy!
No and it's actually good for your prostate to have a release.