What is your favorite store on the citadel?
That one Japanese cafe where the dude really loving excitedly shouts out
IRASSHAIMASE.
Is there a picture of a hive uninfected with the worm
No, because the Hive
are the beings who make the pact with their worms. The beings that came before don't have images, but they're tiny little insect things.
Is there a picture of the fallen without armor
No.
Can the Vex actually be defeated due to its time stuff
I think you misunderstand; the Vex are using time travel to solve their big problem: they looked into the future and saw the end of their civilization; extinction. And no matter how much they try to change time, the Vex always end up not existing any more, and so they keep doing whatever they can to change their fate.