But are still listed as EPs, which iirc involves overseeing storylines. If they weren't doing anything they wouldn't be listed.
No, that's not true at all. Plenty of people get EP credit on shows and continue to get that credit with little to no involvement in the show itself. Maybe they helped develop the show (as is the case with Kurtzman & Orci) but are now producers in name only--meaning they get big bucks for doing nothing. Or sometimes people get EP credit because their production company is involved with the show--usually in that case, a lower level exec who isn't credited is the one doing the day-to-day work on the show.
The EP who is really involved is the showrunner--and that's Peter Lenkov. If Kurtzman & Orci were involved past the pilot/ep 104, it would have been in season one, when the show was getting off the ground.