The Alpha kids’ earth is on the otherside of the kids universe so it took the Red Miles a long time to show up. But they do inevitably reach, it’s how Roxy looses her original self.

Because Gamzee had the strongest kind of armor there is: Plot Armor

because pre-retcon daveysprite was hitching a ride

Yeah..that didn’t happen

Well there’s not much to it, Gamzee went on a rampage and killed everyone before they could play the game

Nope, not that I can find

Possibly? There’s next to nothing on fraymotifs in canon so believe what you like

He says here that he hasn’t had a pie in a long time and here he specifies that he’s all out of sopor slim

She wasn’t that meta until way farther down her storyline

One could debate it’s because John and Vriska were on their questbed/cocoon and preparing the dreamself to die and ascend at the same time.

Or, it’s because the alpha kid krew had their corpses smooched making their dreamselves the main self.