Mike, speaking for myself, I am never uncomfortable singing many Stephen Foster songs.
The songs he wrote for the commericalized minstrel shows were not as enduring in my opinion as the art songs such as 'Jeannie With The Light Brown Hair" or "Beautiful Dreamer."
(Camptown Races excepted of course). Angelina Baker lives on in the folk tradition.
"Hard Times Come Again No More" is a classic.

I believe that these songs that are "questionable" in some audience's minds can be appropriately presented in a historical context. I am not in favor of censorship. Some songs deemed offensive can be presented in such a way to describe negative ideas in a historical context.

This would include some songs that depict Native Americans or African-Americans in a bad light. I think it's important to contrast these songs with those whose positive values I embrace in what some would label "liberal". Again, I emphasize that these songs need to be taken in historical context as an index into the lives of the people who sang them.
For example, "The Unrescontructed Rebel" (whose sentiments I don't agree with) is an important example that needs to be shown.

"Dixie" is one of those songs that needs to be looked at and taken away from the Southern KKK or the New Orleans music publisher that stole the song from Dan Emmett. Emmett was a supporter of the Union and would be appalled that it became the Confederate anthem.

It's a great song which was co-opted by hate groups.

I'm inclined to be interested in folk music from the standpoint of history. History tells us the "facts" of what happened. Folk music tells us how people felt.

We need to know these things.

Frank Hamilton