No, you didn't give "everything" up in 2003. You lost money and workrules. But you also kept more jobs than you should have, pensions stayed intact and so did scope in its entirety.
Again, no.
It's a concession *only* if you get less or nothing in return. If you get something in return, it's a compromise. In 2003,
I'm surprised you or Bob didn't bring up mechanics doing push-backs.
Just because a mechanic once did the job doesn't mean it required the expertise of a mechanic. Stuff like push-backs and deicing were busy-work. Things that were done because the mechanic was there, and couldn't be fixing the airplane while those activities were taking place. They required a bare minimum of skill and training, not a license.
I'm sure mechanics (or their apprentices) probably used to clean up the toilets or sweep up the hangar floor back in the day. Maybe those jobs should return, too?