I think you should make it really easy to figure out how the leader board works and what the prizes are.  Make sure the way you calculate points isn't stupid or there will be nonstop bitching about it. 

If you want to do something gimicky and interesting you could have 50% of the rake collected go towards the leaderboard prizes and maybe have separate.

Also you really should address the rake increase thing before posting anymore big image promo stuff.  It looks like you're trying to bury the criticism which will only make things worse.