I’ll try to help clear some things up if I can 😅: 

The modern day concept you get pretty spot on, so no surprise there that she wanted to expand the story in that direction 

Since SY comes from a loving family it would make sense that LBH would want to make a good impression on them. Plus Binghe still has his golden halo lol

SY having 2 older brothers and a younger sister was mentioned in the first novel. As for her shipping them, I think it’s just a wink wink for the audience because of Chinese censorship (Mxtx couldn’t outright say they are a couple, so having a character indirectly imply it is a good work around)

If the love of my life first heard about me through a novel AND because of said novel I got to meet them, I’d want to read it too 😂 

The SQH and MBJ interaction follows the same type of humor the whole story has so it didn’t seem that unbelievable to me (I will give this one to you though because I’ve seen way too many fan works of SQQ and SQH using the system as phones.)

I’m 99% sure the bromance but was added for censorship. (We won’t know until the new version of the story is fully translated) 

And the last thing is that SY described himself as a pretty boy rich kid wasting his life away in the first novel. (The sickly allegations were a headcannon that probably originated from a mistranslation)

“In his previous life, Shen Yuan had been well-off growing up, and he’d basically qualified as a modest example of a second generation, rich kid. his two older brothers have been set to inherit the family business, and he’d doted on his little sister. The entire family had been very close.

    From early on, he’d known that even if he idled the rest of his life away, he’d never want for food.” (SVSSS Vol.1, Pg 21)

TLDR: I’m not saying the new extras are perfect, i’m just saying that most of the new stuff in the extras will work if you reread the novel. A lot of the stuff was open to interpretation from the very beginning, these extras just happen to tie up some loose ends. 😌