The issue with all of this is that you don't actually administrate Newport on an ooc-basis, but rather inRP. It's a bad choice of wording to call it Administration, the 101st been there and I honestly can tell you that rewording your claim is the easiest way to avoid further discussion about all of this. Which brings us to the next point, it's rather an inRP claim over parts or a majority of the station than actually an administrating of the whole installation. For reference look at the Wall Street infocard.
Corsica Sanctum was like that for all it's time and we even had official laws that stated restricted access to the base, which ofc didn't include any properly ID'd and IFF'd ships for obvious reasons (and before anyone brings up the situation with the Lance that actually started the first OC-war - they literally begged to be shot at with their behaviour).
//Edit: Other than that, restricting access to Newport to ships hostile to the AFC, but otherwise able to dock, isn't what you can do and you shouldn't even try. As mentioned before, inhabiting a larger part of the station, even up to close to all of it, is alright but it needs to leave breathing room for others as well.