If you've got a staff ID and a paystub I imagine you're good. Definitely bring a paystub if your ID doesn't have validity dates printed on it. A friend works for a university and his ID alone was insufficient as it just had his name and photograph on it; he had to get on his smartphone and call up his paystub on the university HR website.
Also they say they won't let you convert an academic ticket to a full price ticket, so if you quit your job before I/O it sounds like they'll just turn you away at the door for not being eligible.
I'm a development engineer at a University, with University staff ID. I imagine I prove this with a pay stub, and staff ID?