I only just caught up with this thread, and that because of comments on another thread about how bad it was here. I'm not usre it is taht bad here. Some overblown irrational raving, but equally some very insightful statements.

Ther are two questions in the thread title, and the second can logically only be answered after the first. Since the vast preponderance of 'catters do not seem to want to reach any understanding of the first any sustained rational attempt to answer the second is unlikely.

If one applies the 1954 definition and related views, there are going to be two problems attached to categorising "rap" as "folk". THe first is that many folk historians and academics seem to see anonymity as an essential for folk music or song, whereas the insistence of modern rap on commoditisation makes anonymity anathema.

Secondly, the pride of authorship means that although some standard phrases in rap get recycled, most modern rap is not recycled in retelling so there canbe no "folk process" in its descent. The form seems to arise from the community, but it is not folkloric.

I would also comment that I don't see "straghtedge" used in the UK music world in the sense that Wikipedia suggests.