One thing I'd add is checking whether the rules match the no-KYC claims. Sportbet.one, for example, states that it doesn't require ID documents, but its terms still allow account reviews for suspected abuse and require 1x wagering on deposits. Those details matter more than the signup page.
I believe a casino may require KYC verification to prevent fraud and money laundering, however it could also be the other way around and use our personal information for the casino's own benefits. So if I have to chose, I will definitely settle with no-KYC requirement, but the thing is, casinos can be tricky too, they will claim to be no-KYC requirement but later on require one, and we have no choice left but provide just to withdraw those significant profits gained.
This is possible. Ever wonder on why we can sometimes get email from a random casino? I heard this is because some casino we signed up with have sold our data's to the other company or casino. That is another level of greediness as casinos are earning well already by default but for those legit no-KYC casinos, we must not worry as long as we don't do shady deals, we will never get questioned and ask for our KYC. They may only require 1x wagering as the other user have said as part of anti-money laundering act but this should only be fine as no details are exposed on this regard and we are here to play anyway.
1x wagering can naturally be fulfilled but based on my experience, KYC-enabled casinos are not asking for wagering for deposits once you already verified your account, as they know already that you are not a money launderer

. For those casino that starts no-KYC and later decide to add it, they should warn users first so that they can prepare. If not, then they are not professional and it may be a worth a complaint.