Shambles, why do you think it would be dishonest to sing "cornbread, peas, and black molasses"? If you acknowledge the tradition whence it arises, I don't see anything dishonest about it.

I think the key is empathy. If you can feel similar feelings to those that engendered a particular song in the first place, even though your circumstances might be different in the particular, why shouldn't you sing the song?

For example, I'm an American and have a lot more English ancestory than Scottish or Irish. But if I can feel sadness at the loss of national freedom through the economic betrayal by the nation's leaders, why shouldn't I sing the anti-English Scots song "Such a Parcel of Rogues in a Nation" even though the particular circumstances are quite different? And if I change a few of the words to better fit the present circumstances, well, that's the folk process, isn't it?