Phil:
You'd also want to check on your US voting rights, again, which may vary by state. I know in MD we have overseas residents who can vote full ballots at their last MD domicile and others who are "Federal only," restricted to just President and Congressional ballots.

Before a US citizen or resident decides to become a ex-pat retiree, it's a good idea to establish "residency" in a non-income tax state such as Nevada, Texas, Alaska, etc.

I don't know the details. Why pay state income tax on your retirement earnings if you don't live there and don't have to?