Alternative Junk Markets/ "Settlements"
While the DMC is clearly intended as the game's major "bastion of civilization" (if you can call an equivalent to Mega-City One "civilized"!), I would love to see pockets of other non-hostiles living in the wilderness.
While it would be neat to have the option to trade/negotiate with random scavengers, I'd be happy with just a few random little settlements existing, dotted far from the DMC out there. Nothing at all on the level of the DMC's city, just a hex or two of a "shanty town" with its own trader (like a less wealthy "junk market" that sells mostly food and low-tech stuff) would do the job.
To me, this would allow you to sell stuff to survive (iSlabs for food, for example) when far out from the DMC, but still mean that you'd need to head back there to really offload your major hauls and to buy powerful stuff.
It would also add a much-needed feeling of "there are still a few people out there who don't kill you on sight, but they don't welcome you with open arms either" in such isolated communities (one encounter even mentioned "enclaves", I believe).
Whether these small "towns" had actual identities (named, with their own descriptions) or were just super-rare, randomly-generated terrain hexes, I'd love to see something like this added.