A Sacrificial Slab exists in the center of the moons of Derse and Prospit. You only need one life to ascend on those. A Quest Bed is located on the player’s planet and you need both lives to ascend on those.

Derse and Prospit exist in the same Medium as the player’s planets so they can just leave their planets and go to the moons just like the Alpha kids did.

Vriska states here that she’s had to kill thousands of trolls to feed her lusus.

Hiveswap is a game about a young human girl named Joey who gets sucked through a portal to the alien planet of Alternia. There, she joins a band of troll rebels and embarks on a journey to save the world and find a way home. A troll boy is switched in her place and ends up on Earth. You can find out more about the game here.

Spades Slick changed his name to Slick in reference to Bilious Slick as a big “fuck you” to the Black Queen since he knows she hates the Genesis Frog.

Aranea states on this page that the Lord of Time hatches in the universe created by the kids’ session so she’s going to try and stop the session from bearing fruit. 

The trolls’ fight with the Black King isn’t shown in-comic but Karkat mentions that Gamzee landed a pretty powerful attack and that Vriska landed the killing blow. There’s also a really cool fanmade Flash video of the battle that you may want to check out.

He hitched a ride on Lowas and was able to enter the post-retcon timeline along with John and Roxy.

Yes, Rose believes that Terezi and Gamzee’s kismessitude would upset Karkat and cause a schism in their group and Kanaya suggests that Rose mediate between the two. 

Yes, the cherubs’ live in the universe the kids’ session will eventually create so we know they complete sburb in the future.