Kurloz woke up from a nightmare and screamed so loud his matesprit, who was right next to him, went deaf. He felt bad about it so he sewed up his mouth. 

Here.

Yes, that’s from this comic by miraculoustang.

“Sollux Captor was most likely named from “Castor Pollux” as suggested by Avi. Castor and Pollux were twin brothers in Greek mythology. In Latin, the twins were also known as the Gemini, of course.” - his Wiki page.

Doc Scratch convinced Vriska to do things she later regretted and even helped. He was the one who distracted Aradia and Terezi while Vriska threw Tavros off the cliff. He also convinced her to mind control Sollux and kill Aradia. He exploited Vriska’s violent tendencies to further his own goals.

No, it does not because when post-retcon Vriska met (Vriska) she was taller.

Karkat likes Dane Cook.

Caliborn mentions here that he knew what his final form would be but he did not know that he would get sucked into Lil Cal to become LE. At least not before he saw his future self in one of the screens on Locam. 

The pre-scratch trolls session had a glitch in it because they weren’t spawned in their session which is one of the reasons they had to scratch. John’s session didn’t have a glitch and he created all 8 human kids via ectobiology. This is why Jane didn’t have to do ectobiology for her team mates. 

Bro is the result of leaving someone with manipulation issues like Dirk’s left unchecked and also living since birth with an evil puppet like Lil Cal which has the soul of Caliborn inside it. I’m not trying to attribute all of Bro’s abusive tendencies on Lil Cal but I think they were definitely accentuated by Lil Cal’s presence.