No clue where you heard 80k usd a year needed that's definitely not the case as many you see post on Here barely make 20k and I'm lost how they think they'll survive here truly.
There is absolutely no amount required to be made per year though if so over half who've applied would definitely not be approved ๐
Absolutely not ! This is not a working visa to work directly with anyone in thailand and it's very clearly stated you can not work in thailand unless it is remotely for clients outside if thailand