Hey OP,
I like it. BitTreasure is more dynamic than mines and bitkong. I just have question about proof of solvency.
According to OP, users can bet "from 0.000001 ~ 1 BTC and from 0.000001 to 10 ETH." and can win "up to 400x on the easy game and 100000x Your bet on the Hard Game." Could you sign a message from a wallet with 1x100000BTC or 10x100000ETH??
I do not think that any admin of gambling site will reveal their bankroll to players since it is not really ethic, more over if you ask them to reveal their address, this will never happens because it is too much risk to reveal everything. But what they can do is to give exactly range like you said about how much we can win. So you just need to calculate their bankroll plus some house edge then you can estimated how much bankroll they have