I agree with most of what is above. All of E1 needs to go and 2 and 3 could be mined for material. To me some of the items that really need to be ported over are the birth of the rebellion (cut) scenes.
It's also nice to see someone else arguing for the complete elimination of Greivous, the weakest and worst character in the PT (yes, I think JJB is a better developed character than GG, they both need to go).
I would much rather see 4-5-6 as standalones and then maybe 4-5-6 with PT content as flashback. I know that the canon material doesn't use flashback but maybe this is the only route for redeeming what little good exists in the three movies.