Re: taxes, the US government will make you pay all your taxes. If you pay taxes to a foreign govt then you can get a waiver for what you paid but if the tribe gives you a good deal the US govt will still demand the rest.
[1] https://www.nytimes.com/2019/01/26/us/politics/allergan-eye-...
It had to do with patent challenges through inter partie reviews (IPR) Basically Allergan transferred the patents to the tribe and said “they are sovereign and thus can’t be challenged through IPR”.
That's the rule for US citizens. You would no longer be a US citizen. Presumably the rules would be exactly the same as they are for current tribe members.
So it doesn't really work.
Yeah, you're right. In Canada, "status indians" get a tax exempt card to avoid sales tax at least. I didn't realize that in the US all American Natives are actually considered US citizens and are taxed federally just like everyone else. Only the tribe itself is tax exempt.
That is according to: https://www.thebalance.com/do-native-americans-pay-taxes-417...
You would also still have US citizenship. You don't lose that unless you formally renounce it.