We don't have any play guns, but I actually think using swords (foam!) and that type of prop in play is healthy and empowering for kids (if done safely, of course.) I've read some research about it and children (esp. boys) tend to play out their fears and playing about conquering monsters and other bad guys is psychologically healthy for them and makes them feel safer. (it's sort of like how scary fairy tales help children deal with fears by working through the worst-case scenario and coming through on the other side, in fantasy. It's an interesting subject.)
My boys also wrestle, and they have been taught by their dad how to wrestle safely and fairly. It's great, fun physical outlet and I think it's sad that some households forbid it. (They also do all of the usual physical activities and sports.)
Having said that, I don't allow gun play where the "gun" (usually a stick or something like that) is pointed at a person or animal. It's my line, and I have no idea if it's rational, but it's partly a safety thing - it's better they not get into the habit, even in play, just in case.