Well, I think Harrison Ford has gotten sort of arrogant. Truthfully I think Han Solo did a lot to define that kind of character rather than it having been quite the same stereotype at the time. As someone who has gone on to become a serious actor, he seems to be one of those who wants to look down on his early work/past. William Shatner was the same way for a long time, but seemed to come around.
Good actor, but I think he needs to be a little more respectful towards one of the big franchises that made him, and a role that he will probably be remembered for, for all time.
As far as the series having a happy ending, Harrison Ford is 150% right about that. As far as I remember hearing, Star Wars and it's lore was planned out before the movies were made, and George Lucas was looking at options like doing it in Japan with an all-Japanese cast at the time in order to make it.
One of the key concepts that was more directly mentioned in the prequels is that idea that the universe works in cycles. A lot of the storyline works around the concept of Fate and Destiny as much as anything. "The Force" isn't just an energy field to be manipulated, but something that literally directs the universe in specific directions. Ultimatly what happens is that the universe works in cycles where Good rules, there is a period of balance (briefly), then evil rules. Few people understand this, and in the "Star Wars" movies we're seeing the end of an era of good.
The prequels didn't convey it well, but a big part of what was going on was that Anakin "bringing balance to the force" was misunderstood as him being there to defeat The Sith rather than the Jedi (the only place for them to go was down since they were in charge). The Emperor *ALSO* misunderstood it, by thinking that the new era of "The Dark Side" could be ruled by him, when he was actually just a tool to bring about the time of balance. Anakin killing him was expected when you get down to it.
See, one thing the prequels didn't focus on (but mentioned) was how "the Force" was cloudy for specific people, there was always a prophetic prescence in the universe, and part of Anakin's entire problem wasn't so much him being corrupted but the universe literally conspiring to make him do paticular things. This is why bits like his mother being gang raped by Sand People (causing him to massacre them in a rage) were important. Things beyond his control were pretty much being made to happen specifically to steer him in other directions, as soon as he'd seemingly have his ducks in a row... BAM! George Lucas wasn't a good enough writer to convey that though, truthfully I think the problem was that the actor knew the role but had a garbage script. The concept was cooler than how it was represented.
As far as the prequels and the whole "Midicholoria" thing, I believe that was implemented badly but was intended to give The Force a tangible prescence to be used in further works. See, when your dealing with an entire story about the futility of human existance, pre-destination, and similar lofty conflicts, there is this natural instict for people to rage "this is wrong" and want their free will. The storyline for "Knights Of The Old Republic II" was apparently in part written by George Lucas and was based around that concept specifically. Kreia wants to kill "The Force", while a disciple of "The Dark Side" she is actually motivated by wanting to give people back their free will (for good or ill). One of the problems with the entire endgame in this storyline is that the bit about "how does one kill a metaphysical concept?" is never really explained, albiet she apparently came up with a way, the first step of which was to kill off both of the major orders of Force Users. The ending of KoTR blows chips due to the problems, however Midicholoria DOES mean that if that is what "The Force" has to work through, by destroying those symbiotes (with another bioweapon or a nano plague or something), one could prevent "The Force" from interfering in mortal affairs.
While I think liscensing issues have so far prevented George Lucas from doing sequels (for reasons I won't get into yet again), I have long suspected that the nature of "The Force" and overcoming it's mechanitions would be the logical next step. Albiet not many people (including most of the extended universe writers) don't get it.
At any rate, "Star Wars" caught on big with kids and I think that George Lucas very much did decide to soften the impact, and ended it on what seemed to be a high note for that reason. Technically the way the story should have ended was with the same basic victory, but a bit of a focus on what was actually coming.
Honestly though, I'm not entirely sure that killing Han would have been the right desician to be entirely honest. Strictly speaking I think the character that should have died would have been Luke. With Luke, Yoda, The Emperor, and Vader all dead and no remaining known Jedi Or Sith the universe would have been poised in balance between purely mortal forces (Imperial Remnants Vs. Republic Remnants) with the big question being which force users were going to rise in the shadows.... (and in this case, it should have been made clear that it would probably be dark ones).
Such are my thoughts.