Personaly, I say make the NFZ count like guard systems as far as engagement goes, and allow any zoner ID to engage anyone (minus sub-40), propper warning provided, if they wont behave.
I've noticed quite often that folks will sit there in transports and talk crap if its a heavy cap, but if its GB or smaller they'll get out fast all of a sudden. They know the rules, and use them to misbehave.
Also, prehaps as an alternative, set up some in-forum RP reporting method for NFZ violations (IE: It's just yoda @ Bethleham, and transports are lolwuting it up) were violators get reported (complete with screencaps of at least incriminating dialouge, preferbly weapons fire too). Once reported, they get their reps adjusted to be just shy of hostile to zoners, full hostile to zoner guard.
They persist, 2nd time they get full hostile to zoner/guard.
3rd time, if possible, LOCK them at full hostile and/or allow any zoner in any ship to engage them without warning within the freeport NFZ.
Personaly I say put yoda in charge of it, he's proably the most impartial one around, and he's been around longer than almost everyone.