I agree with the weapons and general battle tactics comments. First scene, "...the ornithopters shields are only down when it shoots...", <ornithopter shoots>, <missile hits the shield and wiggles its way through>. Why not the first shot then? Overall, whatever, I let go of that type of thing pretty quick. It didn't really ruin anything.
I thought the Giedi Prime arc was great. Good atmosphere, visuals, etc. I wasn't a fan of Feyd's voice and it was mildly distracting. Regarding preserving the blood line, are they specifically preserving a Harkonnen strain? If Lady Jessica was Harkonnen that seems the more important line than Atreides and the are protecting against Paul potentially dying.
I enjoy the 'reluctant hero' trope more than whatever Paul became at the half way point. When he went full Messiah in the South his personality lost me. It didn't seem to mesh with with Chalamet's stature and presence.
If you can see these futures, and you found the one that works, why give up Chani like that? If you 'love her as long as you breathe' and you know the other houses are going to deny your claim even if you marry the emperor's daughter, maybe don't be a jerk. My wife things it is because he is protecting her some how, which could make sense.
The last battle was epic, but felt cut short seemingly like small tidbits of fan service to check off a list. Riding worms, check. Chani's team messing up some Sardaukar, check. Gurny killing Rabban, check. Fin.
I thought the duel in the end was solid. No bending like a reed in the wind here, just full on taking a knife to some vitals.
Another reason it felt odd was that it was hard to root for religious zealots. I am dense, and perhaps it was this was from the start, but I thought the 'Green Paradise' referred to them terraforming Dune with the water they have been collecting. But then the Holy War starts in earnest and the 'Green Paradise' transitions to Heaven(?) instead. This could just mean I am a basic bitch and like a simple revenge story rather than something deeper.