I would seriously wonder about any boy who lost a wrestling match to a girl of the same weight as him. Boys have a tremendous advantage in upper body strength.
Also, when I wrestled in HS, there was a lot of grabbing going on between the legs. It is entirely innappropriate for HS girls to be wrestling with HS boys.
On average, boys are stronger than girls of the same wieght. There are always exceptions, though.
As for the hand positions, it's just part of the sport. If you think that's bad, you should see what goes on in classical dancing. Not all young guys who dance are gay, and there's all sorts of hand positions that might be considered wrong, but not in dance.
Frankly, I just don't worry all that much about such things. It's not as if boys aren't groping girls every chance they get anyhow. If a girl can compete in her weight class and wants to participate, I just don't have a problem with it. Few girls will opt for the sport, though.