I believe the army and police being small mini-factions at the start similar to FBR from Alplands is definitely being proven a working formula (worked well with FTRP as well).
I think with new map changes, there should be whitelist applications before hand to establish a new 'set' faction that servers as an equal, opposing or established force in the new area. already created characters would more or less run into these people are interact with them and set new terms, wage war, be neutral to each other, etc.
The perk system is something that is pretty damn cool that I've never seen so well done in roleplay before. Hard to do with large amounts of people. Could work, but it still depends on whether this would be a full time or a limited time event.