There are several reasons behind the KYC verification requirement. You won't be able to find out each reason by reading the T&C rules of a casino. You will have some idea about the KYC verification requirement through this topic: Information of Crypto Casinos License and KYC requirements

The max bet button is already available for the in-house games of BC.Game. It isn't available for sports betting though. Most of the betting site doesn't have the max bet option for sports betting.