It's... alright I guess. I think I'd need some actual gamzee lines to decide.
I did a quick search of act 1-4 for "all of them" and it didn't turn up any results, so that was probably the first one.
When I first read those panels my first assumption was that it was showing trolls and Cherubs in A2, meaning that Cherubs existed but not necessarily that trolls will exist in C. I can't really remember if it's been absolutely confirmed that Caliborn was raised in universe C or not, but I do remember Calliope implying to Roxy about Universe C being seperate from A and B. Something about a time being more like a wreath than a line in A and B because of all of LE's medling or something? I need to re read Act 6 when I have the time. Too bad I have none of the time. None of it.
As for Gamzee, this panel makes me think that somewhere, deep down, under all the madness and the mind control, he's still the loveable clown who was the nicest troll in all of Act 5 Act 1. I hope there's some way to make him sane again, but there probably isn't.
Some stuff about the cherubs:
I remember reading a post, probably by Bladekindeyewear, about the angels that are a step above Cherubs being Seraphs, also known as Burning Ones, with the red supergiant being associated with Caliborn and the Green Sun being associated with Calliope.
However: According to wikipedia, "the word seraph is normally a synonym for serpents", so you could interpret the Giant Freaking Snake form of an adult cherub to be a seraph.