OP, I recommend you could find your bugs and vulnerables by yourselves, not rely on players losses here. I want to bet on your site, but now I think you may confiscate my fund, why? You claim most bets are double-spends, do you know the current bitcoin network is very slow? And people wait one transaction with 24 hours even they have paid 0.0005 btc, if you use double-spend as an EXCUSE to non-payment, you will lose all customers very soon.