I don't understand why they needed such confidential documents about your identity and your revenues if they just wanted to close your account. If they were investigating something about you and how you place this bet why not asking any question about that?
I wonder if any other bookie, especially fiat and licensed ones has seized customer funds for that bet.
You should read the other thread, they asked their player to submit a statement from the company he worked for, when did he started working, his job title, and so on. Stamped and signed.
If I may ventured a guess, both of this OP and that picked a short straw and meet with a difficult operator. I somewhat "refuse" to think Stake turned themselves into a KYC nightmare for everybody. We'll need a couple more cases [and fortunately, currently there are not new ones] to see if these two are just an isolated cases [thus, a difficult operator] or it applies equally [a KYC nightmare].