GURPS Fallout: Pvt attempting to do something

So myself and a few friends are looking into getting into tabletop RPG's, as an alternative to the constant stream of problems we've all ran into with setting up and running LAN parties. We chatted about various systems and settings, and finally decided to give GURPS Lite a whirl, since it has no setting of its own and it's free.

What I aim to do, since I'll be GM'ing this, is to do a Fallout theme: The players are all plucky members of a Vault in Northern California, sent topside to ascertain if the surface is safe enough to resettle, and find some spare parts for the Vault's failing reactor. As they will be initially starting in the confines of the vault itself and then moving outside, I think this would allow them to get comfortable with the Roleplaying aspect of the game, before I introduce them into the stress and panic of combat.

Since they'll all be virgin Vault-dwellers leaving the place for the first time, I'll have to get creative in introducing them to things that they haven't seen ever before, like Brahmin, Ghouls and the like.

Decided to roll with a totally custom setting, based off of a short story I wrote a few years ago, which was inspired by the Gorgeous Gorgon trope artice on this very site.

Here's the infodump I gave the original three characters (parrallels to Dark Ages Europe are wholly intentional, as history has a habit of rhyming):

The world is different now. Weaker, more wild. Come, children and sit with me, and I shall tell you of the truth of our history.

They don't tell you this in Primary School. They never will. Here at City-State Unification, the Council views this information as dangerous to young minds. So they hide it until you come of age, and an elder, such as myself, is forced to tell you the hard truths that they keep from you for years.

They don't tell you that we're from the stars. Oh yes, child. Long ago, our ancestors came here from a small star, in the Gatherer constellation. Yes, that little yellow one on his shoulder, right there. This was, oh, eight centuries ago, give or take.

The Founders set up the City-States - each one geared to one or two aspects of settling the world. Unification was originally intended to be a farming city - but you knew that part already - and we're still true to our calling to this day. The outlying villages and towns are proof of that, and we have the best wheat and rye harvests out of the other City-States by far. Such fine produce in the bazaar, yes? Just a few coppers, maybe a silver, and one can eat like a Councilman! Oh, but I digress.

For three hundred years, we all worked as one. All was for the glory of our ancestors, our race, our calling to settle this world. But then we lost contact with Home. Even now, no one remembers the name of our Homeworld. It wasn't here, the egg-heads in the University are sure of it. Something about our "dee-en-a" being fundamentally different than just about everything else on the planet. No matter - with contact lost from Home, the City-States fell at odds with one another. Lingering mistrust fell to open bickering, then to hostility. Finally, there was war. And what once united us together, now made us clash and fight, and kill one another. Until the Phage came.

The Phage - a wicked disease, sent by God, or so says the Church, to punish us from our sins of killing our fellow man. The scientists , however, called is a "biological weapon", or something like that. Regardless if it was God-sent or made by wicked men, the result was the same. Only one out of twenty people survived it, and those that survived were horrendously disfigured by it. It poisoned their minds, turned them into mere animals. It was almost better to die from it than to be reduced into an unfeeling, feral creature. You'll know one when you see one - their skin is mottled and gray, and they are irrationally hostile, filthy and uncivilized. The villages and towns were hit hardest, of course, as the Founders had set up the world to be an agrarian paradise, unlike the hellhole that the old Homeworld had become. Technology had been what drove us from the Homeworld, so we turned our backs to it, except for that which was essential.

That decision, to eschew technological progress, is what doomed the villages and towns to death. The City-States, we survived. Being 'declared worthy by virtue of being a Citizen of City-State Unification', we always received our annual disease shots, thus we resisted the Phage. Very few were infected, still fewer died. But I don't think it was the shots that saved us.

Here's why we lived - we shut out doors, child. We shut out the sick and dying villagers. We covered our ears and pretended that they were already doomed, past saving. I was there. I was younger, then, just a child myself, but I can still hear the pleas. Finally, the screaming stopped. The world outside our gates and walls and buttresses had fallen silent. And slowly, we've been reclaiming the lands that were once homes to thousands of our vassal villages.

Did you know that we used to have machines that flew in the air? Aircraft. Not just the little balloons that you see on Festival Night, but things with wings on them. No more. Not even in the museum. Turned into scrap. Why, you ask? I'll tell you why. The world is dying, for we lack the ability to maintain the technology that made our lives here possible. We are sliding into the Dark Ages - indeed, we may already be deep within it. Don't believe me? Just ask some villager in of the distant villages, the ones that survived the Phage. Physics? Mathematics? Electricity? Chemistry? They can barely read, child. You can't expect them to understand the premise behind Celestial Mechanics, or how a Fusion Reactor works, or why the sky is blue. Might as well be magic to them.

Not that any of that matters. No, lads and lasses, all that matters to you is that you work the fields or the workshops or the marketplace, and that you keep your sword sharp, your powder dry and your musket in good working order if the Council decides to levy a draft. Although it's been awhile since we've had to do that, thankfully.

But I've been hearing scuttlebutt in the Market that the Council will be sending out a scouting party to the north. The ruins of City-State Concordant are out there.

Concordant used to make war machines, including aircraft. Planes, they were called. Ones to take people from here to there and back again, ones to take goods, and ones that carried weapons of war. Fantastic weapons. Guns that had rifling in them, much better than our muskets, but at least we still know how to make muskets and fine swords. Oh, we still have the rifles, but we lack the ammunition for them. Just pretty little wall-hangers and reminders of how far we've fallen.

I'll be honest with you, children. You are all of age now. You are all citizens of City-State Unification. Fully vested into it will all privileges and responsibilities.

But the Council are not living up to our namesake. Unification, do you know what that means, child? To unify. To bring together. We've torn ourselves apart, City-State against City-State. And when we were done tearing one another to pieces, we slammed out gates shut and forgot where we hid the key. You know what the North Gate is called, yes? 'The Gate of Open Arms'. How bitterly ironic.

I hope, I pray, that if you find City-State Concordant, that you remember that. Whatever the Council tells you, remember that. Go not as spies or thieves or brigands, but go as ambassadors.