There was plenty to criticize about this movie, but I don't think "Changing the plot" counts. As you say it's another spin of the wheel. What does that mean? Who knows.

I don't think it's as simple as Roland gets time traveled back to the moment he starts to cross the dessert. Probably more like the entire universe has been reborn, if that's the case a lot could change.

how does Jake have different parents?

Jake is an important player in the story of the tower. His parents, not so much. Maybe there is always a "Jake", but it may not be the exact same person.

How is he super psychic?

Magic?

How do Roland & Flagg lose their main focus and goals?

Maybe they learned some things from the last journey? Like maybe Roland learned that if he achieves his lifelong goals, but sacrifices everything and everyone he cared about- it's sort of a hollow victory? Maybe Walter learned a more efficient way of destroying the tower?

Why are the Breakers suddenly children?

Children are often seen to be more 'pure' than adults. Perhaps this is what Walter learned that makes him a bigger threat this time?

What happened to the Wolves? Why are there no twins in the Calla? Where are all the robots? Where the hell is the rose? Is Shardik just no longer in the woods?

All of those events happen after Roland meets Eddie and Susannah.

How did the portals change from basic doors to high-tech contraptions?

You really think that a portal to another world is a "basic door"? Roland describes them as such, but they are clearly either mystical or high tech. Maybe the doors that show up on the beach will have a different design? I like the mixing of magic and tech.

How is it now a 2-day journey across the desert and through the forest instead of months?

As you point out, probably to speed things up. I do wish the movie had been longer.

Why are the skin suits suddenly perfect looking and not droopy/weird?

Looked pretty weird to me. You couldn't have it be too weird without it being equally weird that no one besides Jake is really freaked out by their appearance.

another big one I forgot. 19 should not have been in the movie at all, since it's the 20th cycle this time

Is this a fan theory or was it stated in the books? I don't remember it being the 19th cycle, though that would make sense.