How did Gamzee allow Jack to ascend? Jack used the bunny in the green box to get the Queen's ring, and Bec prototyped himself to protect Earth, so I don't really see where Gamzee was involved. The bunny's timeline is weird but I don't think Gamzee had a hand in any of it.

No bunny involved, Gamzee used his Chucklevoodoos to give John nightmares about Harlequin Jack, which made him draw clowns over his posters, which made Dad buy Harlequin paraphernalia thinking his Son liked it, which culminated in the Harlequin Doll John got for his Birthday. Jack went berserk because the Queen started to tease him about dressing up in stupid clown clothes, and sure he killed her because the Bunny happened to be there at the precise moment with the Royal Deringer, but ultimately, without forcing him to play dress-up, he wouldn’t have gone that far.