One comment that has always bothered me is when people complain about Luke being a "whiner" in ANH. It bothers me because he was SUPPOSED to be a whiner. It's like complaining that Cheerios are shaped like Os. Or that Ferraris are fast Italian cars.
Point being, it was necessary to show the character as being relatively sheltered, young, and naive. It would be the adventure to come which would instill the confidence and "grownup-ness" that makes his hero's journey complete.
It's a similar character arc that Han went through in the original version of ANH. It was necessary for him to shoot first to establish his rogue selfishness that is later replaced by a selflessness.
Without that baseline, the arc, both for Luke and Han, is meaningless. So Luke is supposed to be a naive whiner and Han is supposed to be a selfish rogue in ANH.
Another non-starter for me is the idea that the acting in the OT is "bad." This is an argument usually only dragged out when someone is trying desperately to defend the Prequels. In all the years that I've heard that argument, I have yet to hear anyone point out any specifics of decidely bad acting in the OT. I've yet to see any specific examples of badly delivered dialogue. While all you have to do is throw a dart at the Prequels and you can easily hit examples of bad acting, the same isn't true for the OT in my experience. It's an allegation that no one has ever bothered to back up as far as memory serves.
"The lightsaber duel in ANH was bad/boring." This is a comment that can only be spoken if the duel is taken out of context. Sure, comparing it to the other duels throughout the saga, it moves slower and isn't as flashy. But it isn't meant to be. It's two really old guys having their final confrontation. It wasn't about the glitziness of what a Jedi in his prime could accomplish. It was about Old Ben buying the kids some time to get back to the ship and escape with the plans. Could Ben have finished Vader off in that hallway? Maybe. I mean, let's be fair. If Yoda can turn on the superpowers and dance around like a frog on a hotplate for a couple of minutes, then there's no reason to believe that Old Ben couldn't also become a whirling tornado of destruction too. But he wasn't there to destroy Vader. With the benefit of hindsight, we can infer that Ben knew that to destroy the Emperor (the true enemy), that it would take Luke to "save" Anakin who would then destroy Palpatine. Killing Vader in that hallway would've left Luke vulnerable to being seduced or killed by Palpatine himself. Obi knew that Luke couldn't take that guy on, but Luke could save Anakin and Anakin could then destroy Palpatine. Having a flashy lightsaber duel, ala the Prequels, would have been inappropriate and out of context for the story.
Those are the main "issues" that I read on occasion here and elsewhere.