Do I have to be a cadet instructor for 3.5 years before I can be an S/O (which sounds ridiculous)?
... How is that ridiculous, to have to work in GA for a few years before getting an airline job? Ask most Cathay Direct Entry guys, nearly all of them will have done their first job in something that isnt a jet, and again nearly all will have done AT LEAST 3.5 years in much smaller aircraft.
Uni will help your application if you have little other "Life Experience"