Kurtz was also asked to produce Revenge Of The Jedi - which he turned down for the reasons we all know…
That seems extremely unlikely. After falling out with Lucas, it would be ludicrous to think that Lucas would ask him to do anything for him after that.
I thought George’s beef was with the DGA and that didn’t happen until Empire was finished?
Yes, but that is a different matter. Regarding PGA, that was just my speculation why they officially kept him around, when he was already effectively replaced. It is safe to assume that Lucas did not want to get in trouble with PGA over something like that.