Is laser resurfacing done by gyn too?

Probably, but... Unfortunately, many doctors are performing procedures for which they are not adequately trained. These are almost always cosmetic procedures not covered by insurance that require payment in advance. Your best bet is to see a board-certified plastic surgeon, facial plastic surgeon or dermatologist with experience in laser treatment and the ability to handle any complications.
Not typically. Laser resurfacing is something that is outside the traditional realm of gyn. It is usually performed by plastic surgery, dermatology and ent. Stick with the experts.
Yes but... Anybody can learn, but experience is important. Many plastic surgeons delegate the procedure to somebody else in their office because they are too busy doing surgery. The real issue is can the person who is doing your treatment handle any complications. If not, then it might be time to find someone who can handle complications. If they say there are never any complications, then run away!
No . Usually not, but some doctors will expand the scope of their practice to just about anything.