I had played many online gambling games and many gambling sites in all that I don't even submit my documents to withdraw the money from it.In all that they asked to submit my mobile number and the mail id .Other than that I not even submit any of my proof.If they asked such thing, surely that sites will not shine.
You are right. Since we are using cryoto currency as the deposit option you will not find the any documents or KYC sign up or payment. Some sites from US and Chinese required KYC while singing trading and gambling site.
All the sites we are seeing as a legit gambling site signature and thread promo here. We can use it always for secured gambling.