Wouldn't a completely new bitcoin casino has it's own unique design? It's so so similar to Rollin.io, and I'm not sure why you would copy them instead of making your own design. Really, the only way you will attract people is if you have something different, or if your more trusted. You aren't different, and Rollin.io definitely has more trust from the community. Your maximum win is 7 bitcoin - can you please prove you have the bankroll to pay those bets? You should show your cold storage address and sign a message to prove it. No reason not to.