I have a friend who brings in more money than a large audience, I want to get a percentage of the bets from him
As for me the best choice is to choose known casino with not the best referral program, but without scam. Even if you will get 1% from your friend`s bets - it will be better if your friend will lose everything with help of the cheaters. In such way you can lose a friend and have problems with him deciding who is responsible for the loss of money.