You change the label on a system. That's it. Nothing changes except (possibly) the enabling/disabling of Black Markets and Search & Rescue.
There's nothing you can do in a system that's under the control of a faction that you pretend to be associated with that you can't do with any other system.
You can call that 'territory' if you like, but you're basically no more than a dog urinating on a lamppost.
As for the PMF in my 'home' system. It's mildly irritating, and symptomatic of FDev's lack of concern for the majority of it's playerbase. Happily, I didn't form an irrational attachment to having a particular label on that system, so I'll just move somewhere else - it'll take an hour or two to get allied with the factions there, after which my gameplay will be unaffected.
Maybe, just maybe, if you could get your head around the concept that other people play the game differently to you, and find enjoyment in different aspects of it, you'd be able to understand why your constant demands of "I want to shoot you" are unlikely to be met.