The problem with rules in Beach Volleyball is they differ between areas.
Every region, or even smaller areas than that, have their own set of rules in Beach Volleyball. Its sort of like Street Basketball, people continuously make up, and change, their own rules.
All of the Beach Volleyball games, that I have played, you
could return a serve in set form.
But there hasn't every been a Volleyball game, beach or not, that I have played in that allowed the ball to hit the net while returning a serve.
Though, after returning a serve it was fair game.
I hope I helped out
.