I don't understand why your casino will ask users to answer what is the purpose of using your site, looking at money laundering, someone with the intention of laundering money will not put money in a casino knowing that they will have to play and will have the risk of losing money and also having to run the risk of doing KYC, that's why I think that few people are going to take money to launder in a casino, that move would be a big stupidity, money launderers will look for exchanges or mixer sites, money launderers will waste no time in laundering a few sums in a casino. but the casino must guard against money laundering i just hope these tough rules don't turn away customers
There are games on the casino that has less house edge that perfect for money laundering. For example is French roulette that let you bet on both side of either black or red. The only time the launderer lose is when zero win but he only lose half of his money when zero occur. The chance of zero to appear is very low while launderer can play this game slowly while achieving the casino VIP rewards such as rakeback to cover his loses.
Casino has a money launderer that is why KYC and wagering requirements for deposit was implemented tomcounter this stuff.