Base reward? Do you mean that if my refferal gets 200$ I will NOT get 50% from him?
Is 50% is only for rolls below 10000?
Unfortunately you are correct. For the FREE BTC, you receive "50% of base prize", which is 50% of the first level of rolls I believe.
No, base reward mean only the reward you roll, not including the bonus when you got 100% by play multi or 1000% exchange from RPs.