I think that is a really great idea. I can see how it might help in a couple of ways actually....1. Is the obvious - occupying your mind for a while. Particularly important because you are housebound a lot. Limited mental stimulation at home besides the useual types - books, computer etc...lots of stuff to help you veg out but not much to stretch the mind and imagination. To give your brain a good work out so to speak.
2. Learning something new will give you a sense of accomplishment. Something to feel good about. Something that says I can do this. I think too that learning a language attatched to your heritage would be a cool thing. Not only good for you but it is something you can pass on to your kids (I guess that is 3 reasons).

I particularly like the idea of learning a Native American Language. Again for a couple of reason. As you said those languages are on the verge of dissapearing. But also because as you said so many were ashamed or afraid to admit their heritage. My own Grandfather left home and burned his "Indian" papers out of shame and fear. He died a sad, lonely, drunk trying to pretend he was something he was not. A white man. Learning the language of your hidden ancesters seems a fitting way to show respect and appreciation for the ones who came before us.

Learning Chinese or another language that could be used employment wise is more practical but learning about your heritage will be more meaningful.

Blessings,
Jet