What makes the time-travel bit just bearable in I is that it works emotionally, if not logically. Lois is DEAD, and an enraged, grieving Superman draws on some primal reservoir of superpower we're not sure he knew he had.
Yes. Exactly. You are so caught up in the moment and invested in Superman's emotions that the old reliable deus ex machina doesn't bother you at all. To COPY AND PASTE this into Donner's II, negating the ENTIRE FILM, is just plain silly. In I, it was a matter of minutes. In II, it's a number of days!
And even if you don't take S:TM and SR into consideration, the time reversal is a plothole because of the Diner. In Lester's II, the bully beats up Clark, who returns at the end to teach him a lesson. "Oh, I've been...working out." Great moment. But in Donner's II, no one should know who Clark is, as those events never happened.
Batman Beyond: It would be interesting to see what could be cobbled together from the remaining movies in an effort to make a totally new one. For now though I think our efforts should be focused on getting Superman II right, something the professional editors couldn't seem to do.