-All this is U.S. based not sure how it is in Thai
Banks don't care about you buying crypto. But they do make the process of sending crypto a pain. Additionally PayPal/Venmo will freeze your accounts if you are sending crypto to "dangerous actors". Don't worry they are protecting you. This is now also the case with major exchanges that are more and more entwined with legacy banking systems.
The "elaborate schemes" you may have read about aren't about buying peps. They are more about bypassing KYC regulations that are more and more intrusive. Essentially tyring to use crypto like cash for privacy. Big government don't want any of that. Harder to tax and control.
The basic idea that most of us(and guides) are using are purchase crypto on pretty much whatever platform you want. Then transfer to a more "anonmyous" wallet. Then purchase whatever you want. For example;
1. Buy BTC on exchange (Coinbase,Binance,Venmo,Cashapp)
2. ?
3. Send to Exodus Wallet
4. Send to Vendor from Exodus Wallet
5. Receive little vials of goodies from CNY
Step 1. can still have some delays as they let things "settle". Not always the case, depends on site and how you purchase. Also many people are just buying directly inside the Exodus wallet (which uses external tools to do so). This is more convenient but the price is higher fees and chance of bank account/card freezes.