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?Wouldn't it be funny if they ask for your sexual orientation? Asking about religion is not a big deal and it should not also be something that should be made compulsory to answer because there are people who doesn't have any religion. Any casino that is asking for some strange requirements that you can not even imagine what it would be, that means people will definitely stay away from the casino. The normal requirements like IDs is what most casinos always ask for.