The Oh, 'me' Rosie was put in by some chantey singer, 'me' would not have been used in a minstrel song, unless perhaps it was in a show by one of the UK companies that borrowed American material. Use of 'ye' in minstrel songs also dubious.
The 'Strung up like a banjo, all taut an' long,' also sounds peculiarly salty (chantey) to me.
I looked at the Levy and Brown copies, found no such verse.

Not impossible, but unlikely.

Hugill, in Shanties from the Seven Seas, called "Coal Black Rose" a pure Negro shanty, p. 274 in the Mystic reprint, and elsewhere in that volume refers to it as a "pure Negro ditty," which is nonsense. He made the same mistake with others; one of which likely is Gulf Irish, or Conch, but not Negro.