The novels say that one of Bester's arms is lame.
Is that ever contradicted on screen?
Bester having a bad hand was Koenig's idea from his first appearance, sort of showing that his mental powers outweighed his physical injury. The only time I remember really noticing off-hand is in Season 5, when he needs to put his bare hand on a bulkhead to counter some of the rogue telepaths on the other wide of the wall, and he pulls his glove off with his teeth, but it's definitely consistent throughout the show.
Something about an egg/football piece of Vorlon Technology.
They told him to protect it or look after it.
One mission.
I think that's conflating a few things. The "egg" was a piece of Shadow technology IPX's early probes found on Z'ha'dum which prompted them to launch an expedition there (as far as the crew was told; unofficially, they were already sending probes because they tracked the buried ship from Mars there). Bester, in a throwaway line, was said to have been the one who ordered a Psi-Corps operative to go along on the mission, since earlier encounters with (what they later learned was) Shadow tech had been so damaging to telepaths.
Bester's (secret) grandfather, an early head of the Psi-Corps who was secretly a top-level telepath himself, had had an encounter with the Vorlons. Prior to that, he'd been tacitly encouraging the renegade telepaths and allowing them to grow, on the theory that to develop stronger telepaths, he'd get the best results doing both selective breeding within the Psi-Corps, and having a holistic, evolutionary approach by hunting rogue telepaths and leaving only the cleverest, most powerful of them to escape and have families. After tracking down the Vorlons responsible for introducing telepathy into humans where they were hiding near Venus, the Vorlon gave him a good talking-to about how selective breeding was good and orderly, and evolution was chaotic and evil, so he changed his approach and came down hard on the rogue telepaths, which led to Bester, the infant child of the leaders of the free telepaths (one of whom was the child of the head of the Psi-Corps) being orphaned and raised by the Corps from birth. Bester finding out about this is how he hurt his hand, continuously firing a PPG at the man who told him in a rage, until it overheated and caused nerve damage (though it was heavily implied to be psychosomatic and that Bester's hand had healed fully afterward). The head of the Psi-Corps, meanwhile, had ditched Earth and found a Vorlon planet full of their seed-populations of younger-race telepaths they used to introduce and enhance telepathy in their genetic experiments (since sufficiently powerful telepathy obviated all other social development, as the telepaths could simply hide themselves from predators and induce prey to surrender themselves to them, they lived lives of simple, infantilized contentment, and the Vorlons could only get use out of them by apply their powers in a diluted forms to species that had already developed civilization).
But Bester himself had no encounters with the Vorlons in canon, as far as I can recall. Just dear old granddad.
