My wife was a teacher in Teec Nos Pos for a few years and I rode a few times while on the 'Rez'.
I wouldn't worry about the law if you don't bring any booze/drugs.
The major highways are maintained okay, but not great. I agree with an earlier poster about more loose dogs.
My biggest gripe about riding those roads is that nearly all vehicles are pickup trucks. We all know that 90% of discourtious motorists drive pickup trucks right? I wouldn't expect to get run off the road, but you won't see much love.
Anyway, I think you should do it.
One last thing, be ready for the ever-possible sand storm.