-The Vulcans being such jerks on ENT (though Manny Coto mended that as best he could in the fourth season).
I've heard it rationalized as the Vulcans of the
Enterprise era are meant to represent the United Kingdom at the height of its empire, arrogant in their ways and sure of their cultural superiority in all the areas where their influence reaches. United Earth is the United States pre-World War II, an up-and-coming power who supplants the influence of the Vulcans galactically after the Earth-Romulan War.
-I wouldn't have made Burnham Spock's sister. Perhaps a rival student at the Vulcan Science Academy, and maybe even a former girlfriend, but I think making them siblings was a bit too much.
-Section 31 being so out in the open in the DISCO era.
-DISCO Klingons unless there was a stated explanation, by someone on screen, about why they looked so different. As well as their ships.
I've always had the sneaking suspicion that the only reason
Discovery is set in the 23rd century is that they wanted that familial connection to Sarek and Spock, and whether that was a studio note that they needed some tangible connection to characters we had seen before. Because without that, there's no reason
Discovery couldn't have been set in the 25th or 31st century to begin with.
If you eliminate the Spock connection and redo the setting from episode 1, it makes most of the problems people have with aspects of
Discovery more tolerable. And I don't think having the Sarek/Spock connection does much for the Burnham character. You could have achieved the same backstory with new characters and without having to wedge her into Sarek's family issues.
-Killing off Captain Georgiou, or rather so soon anyway.
Agreed. And they had written themselves into a way of bringing her back at the end of season 1. I thought for sure that after returning from the Mirror Universe, they would bring Discovery back before the events of the Battle of the Binary Stars, instead of after they left, and make it a decision to attempt stopping the Klingon-Federation War from ever happening in the first place. To me, that would have been a better close to the season than the "let's go plant a bomb in the center of Qo'Nos" ending we got.
-The first two seasons of ST: Picard didn't happen.
There's a lot I would throw out. Not so much from season 2, since I think it's just a bad story idea (i.e., let's redo
The Voyage Home) instead of creating weird canon elements. Season 1 on the other hand has stuff like making Mars uninhabitable (we're told its atmosphere is still burning years after the synthetic attack). And making Picard a synthetic is a writing decision that they backtrack from almost immediately after doing it. Instead of saying okay let's dangle how might this affect the character, the writers seem afraid of the choice and have to reassure the audience that, no, this does not mean Picard has any of Data's strength or suped-up-speed or intelligence capabilities, he's just the same-old-Picard in an android body. However, if you're going to make a distinction without a difference, why do it in the first place?
-Change the cause of The Burn in DISCO Season 3.
I think the idea of running out of dilithium had some merit, but the ultimate cause of The Burn they went with was ridiculous. I thought it cheapened the whole threat of it.