If you really want to understand your questions:
Rent a copy of the ORIGINAL, unedited, no-1990s & on re-works, ORIGINAL trilogy (episodes IV, V, and VI).
Then remember that for 20 years, that was the authoritative Star Wars. And no one had any reason to expect otherwise.
Han shot first. It defined who he was -- willing to kill rather than risk being killed or robbed. It also showed just how far he changed, from being the ruthless mercenary to the redeemed love interest of Leia. The Force was a mystical energy field, which could only be truly understood by those like Luke & Ben who were tapped into it (thus Han's skepticism in Ep. IV, at first). There were no simple pseudo-scientific descriptions which would allow a Force Potential to be measured like a lab rat.
Then, keep all that stuff in mind when you watch the later stuff -- Ep. 1, 2, 3. There's a reason why "midichlorians" were never mentioned beyond that one scene in Episode 1. They were a bad idea and Lucas ditched it, just like the over-excessive Jar Jar stuff. He's stated in interviews that he did indeed want Ep. 1 to be more "kid-friendly," wanting to usher in a new generation of potential fans to the Star Wars universe. He thus threw in the silly midichlorian idea and the Jar Jar goofy scenes to make new kids laugh.
But, really, he should have remembered that kids are smarter than that, and that the same tone of the first, Episode IV, of heroism and epic storytelling, work very well. There was no need to pander to the "kids" for Ep. 1; they're smarter than that, and it made both the Star Wars genre and the "kids" he was targeting seem dumber than they actually are.