It definitely sounds like a good idea, but in my opinion it can be improved further:
To protect from making this place yet another battlefield: some level limit, that restricts high-level characters to enter.
To protect from suicide-bombers: add a couple of respawning guards there that are checking your inventory and your hands for anything illegal.
To make this place more interesting to visit: a simple dungeon with low-level creatures.
How do low level beginners can learn anything if there's no experienced dude(s) around? That's why level limit is pointless in that case.
Checking for dynamites - very good idea, I don't know if possible to implement tho.
Place should be interested, yes, but not self-sufficient at all. To gain exp from killing things people gonna go out, not sit tight in one location.
You want to help newbies? Shoot them in the face and take their items. That's how they learn best.
This is what most of pr0 playahs do, I think it's enough.
Safety is going to be the biggest issue with your nuubland. If the npc guards are weak, they get wiped out and the place will be camped by dedicated playtesters. If they are too strong you end up having a new ncr, unless the npcs work like militia and there's players monitoring it.
I thought about guards behaviour like Enclave or Brotherhood does - shoot on sight anyone out of faction. It's easy, makes sense and prevents merc-leader rapists or other trolololo bored kids from camping the place. Player X acts like an asshole? One of important members changes his status in terminal (that's why it's required) and boom! Who was player X anyway?
All hail Sheriff Wichura.
It's not only my idea and for sure not military organization. No sheriffs, drill sergeants, nano-penis leaders and so on.
