Mixing formats, frame sizes and frame rates is not a problem for AE or Premiere Pro. You can either size them to fit the final project or put them in as a smaller asset. Matching frame rates is not that critical either because AE and Premiere Pro will both handle different frame rates in the same project. The frames will be blended or doubled up, or whatever. Of corse you can do a better job of frame rate conversions with 3rd party plug-ins like Twixtor Pro, but there is not much of a problem.
My workflow would be to convert all of the footage to a suitable production format or image sequence preserving and noting the original frame rates. If the footage was transferred from film I would try and figure out if there was 3:2 pulldown added and remove that. AE is good for processing these shots. If film has been transferred to tape and then edited you will have to separate each shot individually and figure out the 3:2 pulldown if it is important to restore the original frames.
Anything that would need to be resized or converted to a standard frame rate would be handled on a shot by shot basis. AE has a better resizing option, but Premiere Pro scales up footage pretty darn well.
Then I would edit the project in Premiere Pro. AE would only be used for processing individual shots or short sequences. There's no need to go outside the Adobe Suite for any of this unless you have some footage that cannot be converted with the AME.
Rick, your answer is greatly appreciated. I will meet with my buddy this weekend, and I’ll share your answer to our problems with him. When you see the frontiersman Jesse Hughes documentaries, “Into the Wilderness: The Jesse Hughes Story”, you’ll know that you’ve made possible our six years of filming and attempting to edit a reality. Again, I sincerely appreciate your assistance.