I thought about taking that route, my concern is that I think flavor and color are served by players having diverse secrets, and I'm not sure how you would achieve that with players individually choosing (e.g., if several of the players all pick prisoner, there isn't the conflict that comes up when one player is trying to surreptitiously steer the course of action away from the camp full of former cops who are likely to recognize him while the rest are wanting to seek refuge there)...

Good thoughts, both the specific ideas and breaking them down more narrowly. Re the involvement in the end of the world, at the moment I have a "scientist" character archetype/class I'm working on that includes that as a (non-secret) defining characteristic, but I like the idea of incorporating some variation in a secret as well...

Thanks!

More thoughts:

-As a general rule, one day in-game == one play session. Of course more time compression where it helps the story, but generally looking at a feel that really gets to the nitty-gritty of every day, and the conflicts and tough choices that come with needing to find food, safe shelter, etc on a daily basis.

-Working on a confessional mechanic used to remove psychological trauma, possibly with additional effects in place of AW's sex specials. When overnighting in a reasonably safe place, two PCs may go off together, exchange some +COM rolls, and potentially remove psych trauma and increase trust (similar mechanically to Hx). In addition, each player must tell the other a secret about their character, either something non-evident about their subjective experience of some on-screen event or something about their background; whatever the case, it has to be something they otherwise wouldn't want people to know (and at MC's discretion, a half-assed secret might require either additional detail, a new secret, or nullification of the benefits of the roll). Together with the one-session-one-day point above, this hopefully would provide a nice breakout/reflection at the conclusion of play sessions, and also tries to get the feel of the genre...

-Early thoughts on a persuasion mechanic; I want this to be at least as detailed as combat. Persuasion of an NPC goes something like this (still thinking about whether I want mechanized PvP persuasion or If I'd rather see that done pure RP):
--MC secretly jots down a short list of things the NPC knows (subjectively, whether or not they're actually true), suspects, and hopes to be true. MC also sets a countdown based on the NPC's initial inclination to trust the PCs.
--Players take turns making rolls to persuade while reciting their actual argument aloud. Different types of argument, as sketched above, match different personality stats, and applied stat bonus would depend on the content of huge argument (MC's discretion; player can say "I'm appealing to reason," and generally MC should give benefit of doubt, but if it starts sounding much more like a threat/intimidate attempt maybe the MC will apply the HAR modifier rather than CAU).
-Each round, MC adjusts countdown based on:
--Success/failure of rolls
--Penalties for statements of fact conflicting with NPC's knowledge/suspicion, bonuses for statements of fact matching NPC's hopes
--At MC's discretion, bonuses or penalties for particularly convincing or unconvincing arguments
-Rounds continue until countdown hits max (NPC is persuaded to players' course of action) or min (NPC done talking, depending on circumstances ranges from just unwilling to keep talking to running away/locking a door to open hostilities)

I'm thinking about starting a hack set immediately after an apocalyptic event (probably keeping cause vague/fluid), like in the first weeks and months. I thought of this after noticing a distinct lack of early-apocalypse RPGs (at least in the non-zombie context). Think Day of the Triffids, The Stand, etc. I feel like this setting, with its focus on ordinary people adapting to a new reality (contrast deep apoc, where everyone has either survived this long or was born into wasteland life and so is definitionally likely to be at least somewhat a badass), and on conflict between survival at all costs and holding on to/rebuilding civilization is good fodder for storytelling/character-driven roleplaying.

Some ideas I'm tossing about:
-Stats focused on character/personality play a central role
--Opposed stat pairs, still working on mechanics (see other post)
---Opposition will both impact character development and drive character interaction/conflict
--GUTsiness: Acting under fire (similar to cool), getting the drop; opposes CAU
--CAUtion: Checking for danger, searching for supplies; opposes GUT
--HARdness: Hesitation check when making first attack against non-openly-hostile human or docile animal; opposes COM
--COMpassion: Relieving trauma, reading people; opposes HAR
--Two simple aptitude/ability based stats, FITness and WITs, play a mostly secondary role and naturally converge regardless on starting point (the longer you survive, the more get into shape and  learn the ins and outs of survival)

-Four-stat persuasion mechanic: Dealing with other survivors always carries the risk of violence, but any survivor who turns to it as a first resort will not be a survivor long. To this end, each personality trait has a persuasion method associated with it, with likelihood of success of each varying by circumstances.
--GUT: Appeal to expediency
--CAU: Appeal to reason
--HAR: Threat of force/intimidation
--COM: Appeal to emotion/humanity

-Story-based advancement: When choosing advancement options, a player must justify that choice by reference to story events--for example, to take a plus to a personality trait, player must reference an event that had a galvanizing effect and describe why it had that result. E.g., "When we shot those looters, and I saw that kid lying dead on the ground—he couldn't have been more than 14—I realized how important it is that we hold on to our humanity; if we lose that why even survive?" (+1 COM), alternately, "When we had to take down those looters, I realized it's them and us in this wasteland—and damned if I'm going to let it be us." (+1 HAR).

-Starting character archetypes ("classes") based on pre-collapse life (some ideas: law enforcement, medical professional, counselor, office worker, construction worker, farmer, doomsday-prepper, criminal), with advancement initially tied to background but eventually gaining access to broader category of increases

-Physical and mental health—in addition to tracking wounds, characters rack up trauma for experiencing the horrors of survival, sources of trauma may vary based on stat values or background. Higher trauma levels have escalating effects, eventually up to and including total breakdown/permanent personality changes.

-(aspirational) Scalability from wandering band of survivors through crude strongholds through building new society from the ruins

Welcome thoughts and suggestions!