Pretty awesome, that you learned some Dakota! At least it gives you something to work with, if you wanted to expose your kids/nephew to it. Bilingualism from childhood is a really powerful and amazing gift to a child, and really it doesn't matter what the languages are: a heritage language is as good as a major national language.
The dual-language immersion programs are really awesome; I've seen kids from monolingual English families learn to do all their math work in Spanish by the end of kindergarten. Teaching kids language in that way is so much more effective, I hope those programs only become more popular.
1) My parents and I recently took my 5 year old nephew with us on vacation to DC. He tends to sing at that age. We were in an elevator and he started in on a song and a couple from Spain started asking me questions about it. I really could only say he was being taught Spanish at his school.
2) I just cannot do a guttural with my voice. It sounds like I'm coughing. I have such a low voice anyway that it sounds wrong all the way around. At least I learned from a male instructor, that's a bit important as the sexes speak differently in Dakota. My old boss, a female, learned to speak from her uncles and her aunts thought she "spoke like a man".
3) I still do server names in Dakota. wanca is my #1 server.