I can’t see this going past season 3
The first 2 episodes it’s clear that Barry is a psychopath, if he wasn’t one already. Yes his girlfriend is also a psychopath, and that has probably unleashed his inner psycho.
The audience will struggle to find any redeeming qualities. The only possible way there’s a S4 is if Barry repents and confesses to the police and S4 is set in jail. Maybe Hank is there too, because I can’t also see this guy keep running from various mobs for much longer.