My 2 cents:
The story should be about people. A lot of players who play with supernatural Endowments and psychic abilities and thaumaturgy want the story to become about their phenomena. It's about their hellfire and demon wings and ability to make the air cold. These should be, at best, and even in Second Sight were described as, doing what you normally could do, but with an alternative capability.
I can put my ear to the door and hear what's going on inside, but you clairvoyantly do the same thing, and she uses technology to accomplish yet the same feat. Different strokes, for different folks, but the story should be the same, the Storyteller tells you what is going on inside, given success.
All things being equal, no single element of the game should trump any other element, so surviving whether by pikes, guns, traps, staying out of reach, walling yourself off, running, convincing someone to do the fighting for you, or psychically throwing zombies away, should accomplish the same goal: to not get bit, to not get scratched, to not contract an illness and die, and rise again. To find water, and shelter, and food.
Working together should bring about things like infrastructure, and that should be a game unto itself. The casual player should be able to log in and have fun, but the canny player should be able to find other like-minded players and create something of value to them. Enough people working on it, can make the local water plant produce clean water, just the same as digging a well, or tracking a fresh spring down. Enough people on it, can make electricity by wind power, pedal power, solar power, water power, etc. The casuals should be able to get by without doing any of the above, just not reaping better benefits in the process. (E.g., they can have gear, just not the best gear in the game.)
The true story is in whether any given faction tries to take from others - that's what makes it survival horror. Do people sacrifice one another, so they can escape. Do people hold up traits like character, honor, decency, and try to avoid barbarity. Are the rules for doing so any better than what the barbarians are doing? E.g., is the ex-lawman's willingness to execute people at the end of his guns in the name of justice any different than the cannibal gang willing to eat their neighbors for a good meal. Your Morality system should be a central emphasis for both casual and hardcore players.
I think regional issues are super important to the overall story. Who is checking on the local nuclear reactor? Is the pressure in the damn upriver going to eventually be a problem? Is there any kind of fallout from burning cities, burning states, such that weather becomes a factor. Was there enough widespread destruction that nuclear winter happens? It isn't just about finding a place to grow crops. That works if you are distant enough from civil engineering that you aren't in a situation where the things we have - that we never consider - that protect us from man-made dooms like floods don't, unmanned, become catastrophes. If the collapse of civilization is fast enough, has no warning, then a lot of systems are left unchecked. Not everyone turns the light off and walks out with a secured facility. And I don't know about you, but I sure don't know how to turn off a freakin' nuclear reactor.
This isn't even mentioning things like blizzards, hurricanes, tornados, pick your region, and the like, which now can come upon us without warnings we had in the past. Can you tell if the sea is rising for some reason fast enough to make escape from coastal regions possible?
The average person likes to believe they are pretty capable, but when the chips are down, the people who know how to swap out a part on an engine, or even the difference between types of engines, know the difference between something poisonous and safe to eat, know how to check water's safety, know how to start a fire unassisted, know how to keep smoke from signaling others that you're there, know how to live in the wild without power bars and mountain bikes, know how to survive in cold or hot conditions for really real and not with their REI purchases, know how to conserve and make choices like what's more perishable and what's more collectable. They're few and far between, and not every PC will have the Streetwise, Survival, Investigation, or Academics and Science to know. Even ranch hands and farmers don't necessarily know what you think they should. Every skill should count, from Larceny to hide your food, to Politics, to sense if the new Mayor is in fact a cannibal, and the Merits that you allow should be extensions of them. Again, the casual player can ignore nearly everything, but the hardcore player should be enjoying the process of wielding what they have traded their Experience for, and reaping the failures of what they're not covered for.
Finally, I highly suggest creating an actual inventory system so that people can play that mini game of collecting things. These give tangible benefits already within the system, like bonuses to rolls in Skills. By making everything have uses, from a bar you swing at something's head, to the rounds in a gun, to the number of times a door to your hideout can stand an assault, you can obtain something and have to re-obtain it, meaning that the benefits are constantly wanted while the casual player simply goes without them.