The problem i can see with the creator being able to kick players out is as follows...

My brother plays the game StarCraft (if anyone is familiar with it). Anyways, quite often, people will create a game, and ban anyone who joins for no reason at all. The game sits there forever, never starts, and takes up space both on the server and the list of games screen.
I can see this happening here too...someone will create a tournament, kick everyone out who joins, and it will never start - just remain on the list forever.

Although, i still think its a good idea, because that likely would not happen very often.
And I agree with the private tournaments as well - good idea :-)