I haven’t really thought them out, but they’d be pretty similar across the whole cast, like being able to run or walk, climb things, etc. Heroes that currently have movement abilities that would become universal will have superior ones, for example Hanzo/Genji can climb any surface, but other heroes can only do so if there are rungs or ledges or something.
He has 100 hp. So yes, there will be stuff that can one-shot him, but he moves at the same base speed as heroes bigger than him, and would probably have a special movement ability as well, being a scurrying hamster and all, so his little hitbox would be bloody hard to catch.
Yes, they do! There will be some kind of thematic difference between Torbjorn’s and Symmetra’s, though, so Torbjorn may be better for fortifying a point while Symmetra is better for manipulating the map, but there’d be some overlap so you’re not totally forced to pick one over the other.
But most importantly, Junkrat would get his line back.