Hi tomand, welcome to affiliate marketing.
in reverse answers (3) not too sure about us I focus on uk – it is a bit unusual to have an aff program that is based off player winnings. I would say you want it the other way as if people made money through the casinos then they would not be in business or so the old saying goe.s. other people on here my disagree but the is IMHO.
1) link exchange is a tough call, you can look at alexa rankings as well as google pr however I personally try to steer away from link exchanges as I don’t want to have ap,a effort all shared links for fear that google might see me as being spammy.
Good lluck