Well, all of JJ’s movies share a lot of similarities because he’s got an identifiable, strong personal style. But Into Darkness, save for the very poor decision to sample the ending from Wrath of Khan and invert it despite it not having any set up (or real point, considering we’d already seen at this point Khan isn’t even the real bad guy in the film, more like an antihero), had some similar problems, but it also wasn’t as incoherent from a storytelling perspective. Almost all the beats it was trying to pay off were set up and investigated at least a little. It’s not a successful film overall, but there are more effective moments in it, and those moments are more competently strung together. It’s a much more consistently constructed and executed movie than The Rise of Skywalker.
I was going to click the reddit link but it appears to come from “Saltier than Crait” which isn’t a subreddit that’s ever had much worth or value as anything but a gall-bladder for Star Wars. There are much more reliable places to source information from than a place that is essentially a self-described salt mine.
Fan fiction isn’t just for people who enjoy shipping. There are lots of places online where fan-fiction is how you play the game of “this is how I would have done it if I were in charge” and so people write very involved stories using real-life figures as the characters in a Lifetime movie.
Anyway, the “Darth Vader’s Death” music is 100% from Return of the Jedi, it sounded to me like they took it from the CD, and it’s very oddly edited on top of that.