See hun, I don't think you are really RNG abusing... just misunderstanding what it really is, lol. You should definitely be using a computer program to predict what pokemon the game will generate. o.o There's a guide in Trade Corner
For Mewtwo event: Turn on Pokemon Black or White. Instead of clicking Continue game, go down to Mystery Gift. Click Receive Gift. Click Yes at the prompted question. Click Get Via Nintendo WFC.
For Rayquaza event: It's in a place in Japan, sooo you can't really get it from wifi. That's all the events I think are happening.