5. To prevent abuse and ensure a fair gaming environment, users must complete KYC (Know Your Customer) verification before participating.
No. KYC is not mandatory but just like other casino, they may ask you randomly. The promotion that you mention is their way to attract new user to undergo KYC just to get the bonus reward.
I still have my account not verified until now but I rarely play on this casino these days so maybe this is the reason why my account is still not ask to KYC even if my account age is old enough.
"must complete KYC" doesn't sound like it's optional. If it only refers to the promotion, giving personal information and passing KYC is too much for a $20 bonus. I understand that it is a question of protection against multi-accounting, but there would have to be some other way to make it happen.