Rule #1 It's simple. Yes, you can't not hit the ping pong ball before it bounces on your side. If you are playing at work and someone keeps doing it to you claim it as a rule that you can't not wait to hit the ping pong ball before it even starts to bounce but must wait till after the ball is not hit. Basically, you can do whatever you can enforce. If you say anything with enough conviction to someone with less conviction - then that's what becomes the rule.
Rule #2 You can catch the ball over the table and claim the ball was going to be off the table and give yourself a point.