I think Garnet made it pretty clear what bubbling is when she said "in stasis"

Pearl has used her gem as a flashlight before.

I'm curious. If the weapons are less an aspect of the gems and more a thing made someone for an express purpose, then how do the fusions' weapons actually work?

"but it’s hard for me to see that as necessitating the reformation of Malachite, rather than some other fusion—"

Everyone's hair looked particularly big this episode, especially Lapis's.