What the US really needs to do is blank slate all the Indian laws, treaties, agreements, etc. and create new ones to handle the issues.
Including in that re-do would be settling all outstanding issues and establishing very clear and explicit rules for how tribes are dealt with in the future.
Honestly. All tribal citizens gain the automatic, absolute, right to have any legal proceeding to which they are a party removed to federal court and judged under federal law. With the caveat that if all parties to the suit are members of the same tribe then the federal court will apply that tribes tribal law as well.
All tribal citizens are immune to all state or local taxes save consumption or real estate property taxes.
Recognized federal tribes can acquire ownership of lands and when they do so that can (under some circumstances) become tribal lands that are outside any state regulation of them.
It would take a constitutional amendment, but I would support creating a "Indian" state that gets their 2 Senators and 1+ Representatives (and the associated electoral votes) with all recognized tribal citizens (regardless of residency) being the voter base for that representation.