It has been a while, but I'm pretty sure the bladed weapons are needed because the shields specifically block objects with high kinetic energy. I also recall one of the houses on arakis getting bombed, but only after they were able to turn off the protective barrier. I might be mixing up Sci fi books, though.
You’re not - it’s pretty explicitly the point. The technological arms race has gotten so advanced that everyone has devolved into fighting with knives.
You are correct. But the movies did indeed make a poor introduction to the shield technology. I think it was just a short mention when Gurney is training Paul and is easily missed. They even have to train for a specific fencing style that involves slow movements as a fast swung blade can still be stopped by the shield. And I don't remember them talking about the interaction between lasers and shields at all, which creates a huge explosion.
My bigger issue with the movies was the typical hollywood charge. No tactics or strategy involved at all. Just screaming and running.
My biggest gripe with the movie currently is that when a Crysknife is drawn it must draw blood before being sheathed again. If you don't use it on someone you must cut yourself. This is explained to the reader in the book, but in the movie it includes the scene where it would be explained but isn't mentioned. It's not a huge deal. They can just ignore it. However, at the end of the movie the Fremen have their knives drawn and it focuses on them cutting their hands to sheath them. I'm sure people who didn't read the books before seeing the movie would think it's really weird, especially for a culture so obsessed with water (although I don't recall if they've discussed recovering water from blood yet).
The shield-based fighting style was also a small note that was missed in the duel between Paul and Jamis in the movie. Paul was missing what they thought were clear cuts and as a result they believed he was cruelly toying with Jamis, but it was because he was slowing his blade at the very last moment due to shield training.
Also a slightly weird moment for me as a book fan was when the thopter Duncan escaped in clearly showed that it had shields with a rock crashing off of it, but then he was being chased by lasguns immediately after.
Laze guns interact with the sheilds causing basically the destructive power of Tsar Bomba+, but knives/swords (when used properly, as Gurney Halleck taught Paul to do) pierce the sheilds. Read the book nerd.
The movie had its problems and I've never read the books but even I know the answer is because the shields don't stop slow moving objects otherwise you wouldn't be able to pick up a cup. It's even explained in the film, admittedly very briefly.
But then again that's also how personal shields work in Stargate
Also a laser hitting a shield causes a massive explosion, which could be at the shield or laser gun. Bullets get stopped and a laser would likely kill either user if many kilometers away, or both of closer.