@Greg *******
I went through that hassle with North Carolina. I think every state will be different. Basically, NC felt that since my mailing address was NC I needed to pay NC taxes. I raised complaint and they told me I could go to the other jurisdiction and request a credit. That was stupid advice but my taxes aren't their problem.
This year I moved to a virtual mailbox in Texas and have none of the state taxes deducted. The point really is the address on the W2 is key. Also, getting money from a government body is more difficult than paying them.
I may be able avoid federal taxes but that would require I pay taxes in Thailand, which requires work, which requires work permit, which require....
I will collect Social Security from the Federal government so I am content to continue to pay federal taxes.
If you have proper visa you probably can open a Thai bank account. I just transfer my living expenses to my Thai bank account monthly. I can not deposit checks to my US bank account, (you know photo of the check uploaded in the phone). My bank detects I am not in the US and they don't allow it. Virtual Credit Card is a service my bank offers but only kinda works in Thailand. Most of the day-to-day stuff will be cash based. I pay rent in cash, buy groceries cash, etc. etc.
Good look and watch out for sick Buffalo.