4.) But even after I did go through full KYC they are not releasing my funds.
That's not right at all... You should be allowed to withdraw your funds to the address you sent them from, at the very minimum. What I recommend is to post a comment describing your situation in their
main thread and see if the KuCoin Exchange account replies to you. They may be able to help you out quite a bit as they were just online today. If that doesn't work, reply back here and I will help you to open a formal scam accusation against them, which might stimulate them into action.
Depositing and withdrawing funds, without making trades, is a huge AML red flag. Exchanges are basically huge mixers. If you deposit funds into an exchange and withdraw those funds there is no way to trace where the funds are going.
Not a valid excuse to hold somebody's funds without any sort of way to get them back. Exchanges are only decent mixers if they are completely anonymous, like a DEX, and even then there's ways to see who got what, where its been, and where its going. Exchanges that ask for KYC are the exact opposite of mixers.
And of course there's a way to trace where the funds are going, its called blockchain analytics.