I completely agree with your reasoning and you should just keep it to the six films without regard for EU or ST. A few logistical suggestions for Adywan, if I may:
1) I would begin to expand your team. You are certainly quite talented and should have final say over all elements, but I think you deserve help. Emanswfan is color correcting the PT to look more like film and better match the OT. Pulling him officially onto your team could get a lot of the work done faster. He also was willing to take over the ROTJ project I first suggested, so he certainly has the enthusiasm to help out on that film (not to mention he likes a lot of the ideas our little group came up with together ;) ).
2) I know that your primary effort is to make to PT match the OT and not the other way around, but a few minor changes to the OT will drastically ease that transition. I believe Brash pointed out how to fix such things in the Unofficial thread, and I believe that at a minimum Obi-wan's mention that Vader was a pupil of his should be removed from ANH. It's not quite the purist thing to do, but unless you manage to film and composite a new apprentice and convince everyone that this new character is interacting with Obi-wan and other characters and is the one to turn evil, I think that simple line removal is the best way to ease that problem and allay the audience's suspicions.
3) Victory-class Star Destroyers are non-negotiable and must be included, preferably in ROTJ, though I wouldn't mind additional inclusion in the PT ;) Okay, maybe that's not very logistical.
4) Also more of a story suggestion, but I worked with daneditor to come up with a way to give Boba Fett a more deserving death. And considering all he put together came simply from various fanedits of questionable quality, I'm sure you can put something even better together and fit it into the movie in a similar way. I urge you to check out his experimental and incomplete edit to see what he did.
5) I know emanswfan did wish to take over the Collaborative ROTJ edit, but that is far down the road. If he were to join your team as I suggested in point 1, I encourage you to consider several of the other ideas we came up with together.