And also any chance to accept other altcoins ? because you have already mentioned about the almost 20$ fee in every deposit from 50$ so how much will gamblers has to make their plays?
Forget about those posts of OP where he talks about when you deposit $50 you will be credited with $30 because the rest will be used as network fees. It doesn't make any sense saying that because those fees are paid from the balance of your private wallet and not from the total sum that is being sent.
He only considered exchanges when he wrote those posts. When you initiate a withdrawal from an exchange, his logic makes sense. If you are withdrawing 0.1 BTC, you have to pay 0.0005 BTC as withdrawal fees. That means your address will only be credited with 0.0995 BTC. But if you send from your own personal wallet, the 0.1 BTC will be credited to your betting account, and the 0.0005 BTC (or whatever fee rate you used) will be taken from your remaining balance.