If exchanges find out that you're faking your name and your KYC details, best they can do is freeze your assets and close your account.
If you've already managed to deposit or withdraw some fiat under fake credentials, the exchange in question may pass the details it has about you (such as IP addresses, bitcoin addresses, etc.) to law enforcement to cover their own asses from an AML point of view.
You can always use bitcoin ATMs but the fees aren't worth it, IMO.
Agreed, but there are other options which don't require KYC, such as BISQ or localcryptos.
Nope. Read their ToS and use it against them should they do something unwanted on your details.
That sounds great in theory, but in practice most exchanges have such an all-encompassing Privacy Policy or ToS that they can essentially do anything they like with your details or documents. Take a look at
https://www.coinbase.com/legal/privacy or
https://www.binance.com/en/terms. The list of people they are allowed to share your information with includes pretty much everyone, from marketing agencies to data processors.