Initial question, after thought, seems easy to me. A regional dish becomes national when it is served with regularity and success outside of it’s "home" region. The trick is if it remains linked to it’s birthplace. Cheesesteaks will always make me think of Philly and that they would be better if I was in Philly, where ever I get them. Jambalaya, I think Louisiana. The rest you listed I can’t think of or don’t automatically associate them with an area. They are foods of the people.

Thai Food kind of has it’s links in the name and I will not sit at a sushi bar with an Irish guy holding the knife.