First of all, chain-bet is not my website.. I just played there a few times.
The difference between chain-bet and your site is, that chain-bet moves the bet amount from the generated address to their hot wallet. So every player can verify that a bet amount was placed to their wallet and not a different address not belonging to chain-bet. At your site i can only see the coins on the generated address but no one knows your hot wallet.
So if you don't want to move the coins to your hot wallet, I would recommend that you sign the bet address with PGP so people can check if the generated address is yours.. Here is an article how to do that
https://libraryfreedomproject.org/how-to-pgp-sign-a-message/Your claim of Chain-Bet players being able to verify that the bet was placed to the correct site isn't valid, as if I were Chain-Bet, I could easily scam people by sending the BTC to another address instead of the the hot wallet. Neither Chain-Bet or Block-Bet have systems in place to prove that the address is indeed their address. PGP signing is a good idea though.
Your absolutely right. I didn't consider it that way..