Some of the interpretations in Old Mother Hippletoe are stretched too far.
The verse you quote from "Jim Crack Corn" (from Hippletoe) is from a song in Randolph called "The Crow Song," verses of it or similar songs appear in Odum and Johnson, Perrow, Talley, Cox, Harris and others, stories as well as songs, but has nothing to do with either "Jim Crack Corn" or the "Blue Tail Fly" (see threads, originally separate minstrel songs that became united).
The writer of the blurbs for the recordings has slipped a cog or two. I'll read through some of it as I get time, but I get the feeling that some conclusions need to be taken with a carload of salt.
My take on the 'url'- Hippletoe (May not work either- pdf sites give me trouble too)

Byme by, I agree is by and by- I remember old folks who said By um by, and I think it is the same sort of expression. Whether it could refer to the old spiritual By(e) and By(e) I don't know.

The black snake bite on the heel appears in both White and Black song- why the poor black snake had such a bad reputation I don't know. In White song, goes back to Colonial times. Threads on this one.

Lines and verses from one song float to others, so many songs overlap.