Have you thought of adding the 30-post rule to BL too?
I second this. Whatever it takes to remove certain types of people from the league is good.
No.
The main reason is that bl's existence has two reasons (imo) :
A) test unupped metagame.
B) be a starting stone for new players to improve and become members of community, both from acquiring pvp skills and chatting with opponents
I haven't been aware of major amounts of cheating in bls (i can only think of last seasons' multiple accounts), so the grounds for the 30 post rules applied to tournaments vanish.