Is it considered gambling to run contests that require entry fees than give the winner of the contest all the entry fees? I've done some research and it seems that as long as its a contest of skill, then everything is ok. Is this correct?
It depends where you live and where you operate. You need to check your locale statutes on lotto, raffle, etc. Next, you need to void your contest where such things are prohibited by law. There are always laws governing these things. Do you homework to avoid getting in trouble (civil and criminal).