He said at the time that it was deliberate decision so I assume that Neeson's reluctance to return complicated his grand plan, just as DiCaprio's reluctance to join on did.

Assuming there was a grand plan.

I find it hard to believe that Jar-Jar wasn't going to play a greater role in the series until his near universal unpopularity forced Lucas to ditch him.

There are so many circles to square in the PT but that's part of the fun, there's the challenge.

If Jar-Jar could be made to work with re-dubbing it might be worth replacing Threepio with the new improved version.

In some ways spreading Jar-Jar about may be more radical than taking him out.