Can you give example of the unreasonable request you meant? Even if the casino request for passport, drivers license, or any valid ID, it is still a valuable secret information. If the the casino doesn't ask for proof of address, they can use the customer's IP address to locate the person if there's need to do so. Also, there are some casino that doesn't ask for KYC information until you want to withdraw.
Well, everything you mentioned is common and normal for them to ask. By unreasonable, I mean something outside of that norm. And I don't have any examples to give you; they haven't asked for anything different yet, but use your imagination. What would be strange if they asked you? I don't know, your sexual orientation, your religion?