what I would keep:

Qui-Gon

the nature of the "prequel" Jedi (in that they forbid attatchment), ans there are signs that Qui-gon planned to go against that doctrine (namely because he tried to free Shimi as well).

that's actually the SOLE plot point from the "prequels" that I like, because it DOES make Luke's Journey in the OT much more meaningful and that journey's end in the Undestroyed Return of the Jedi all the much more uplifting.

also, believe it or not, I would also keep Jake Lloyd, because he actually looked like he could grow into the REAL Anakin Skywalker, Sebastian Shaw.