Did you actually think this through before commiting it for comment?
I enjoy doing missions from my 'home' station that involves 'taking care' of dissidents, deserters and (BGS influence) even civilians, very often in the same adjoining system. I will be a criminal completing any of these missions... Yet you are suggesting that by taking on missions to support my faction I should be banned from a system for doing so? Somehow I am unable to put my support behind such a suggestion, sorry.
I would like to see this implemented in your particular instance, then have you being fined for taking too long to clear the pad/station a couple of times
Think about how many 'crimes' you can commit just leaving or entering a station, then apply your solution...