I think the ST era future is definitely avoidable. Star Trek, Zelda, and other franchises have other timelines. Star Wars having more than one ongoing timeline would both "sides" of the fans happy.

I never liked the original all that much. Especially when I saw him easily be defeated by a child with a pipe. Not sure if that was the first or second film, but still. I quite liked Joel in the role. But Peter Weller is of course an iconic actor.

Raava has never been shown to have the ability to exist in more than one person at a time and I would prefer they not break that. Raava shouldn't be able to split into two, as she is one spirit. The other twin shouldn't be the Avatar, just a normal bender or even a non-bender.

If something from the past is referenced, that specific thing becomes canon. If it isn't mentioned, it likely isn't canon. So for example, Waller's scene in Black Adam right before Cavill Superman showed up. Still Viola Davis, likely had the same experiences as DCEU Waller for the most part, but that specific scene likely not to have happened in her past.

This wasn't confusing or upsetting to me at all. I figured if Din had an actual blood related child he would be Djarin but since Grogu is adopted he takes Din instead. They never confirmed that but that's just what I figured.