Or perhaps op could let players drop an address and a signed message from it (sign of ownership) as an alternative login. Maybe it'd feel less threatening for other folks too.
They will not be able to deduct from the accounts as the players bet if the private key is not shared. I will assume they need some sort of smart contract or 3rd party service to effect deductions from the wallet.
Adding this feature brings up a big question mark about trust and I believe it will be better for a new casino to operate as traditional ones, not generating new keys or requiring private keys to log in.
- Jay -