1. The main issue you might run into while transposing settings is that you need some form of reassembly—it’s completely core to the game. Players could in theory come back as different characters (i.e. a new Helldiver being taken out of cryo each time the last one dies) but players need to be able to die and come back next round for the game’s systems work at all. Besides that, you’d need to draft up new FACTION TRAITS or tweak the existing ones to fit your narrative, and some CHARACTER TRAITS, BONDS, and ROLES/SHTICKS might need narrative adjustment, but I think a lot of them would transpose well to any dark-comedic military scifi. A lot of the items/weapons require a certain amount of scifi for their mechanics to make sense, but again, that probably isn’t a big deal. You may also need to tweak/add CLASS TRAITS if you want different primary combat archetypes, but again, I think they’ll transpose decently. If you want to discuss this further, I’d be happy to give more specific thoughts—and honestly would love to just hear how the process of adaptation goes/plays. You can email me here to get an invite to the PLANET FIST Discord server, where I’d be happy to talk it out! Lots of design discussion happens there.
2. At this point, it’s pretty distinctly its own thing, so it won’t necessarily be easy, but also, is definitely possible. It also really depends on what sort of materials you’re adapting. Maps & mission modules are on the tougher end, because PF’s reassembly system, map-based combat, etc. require some pretty specific mission parameters and geography to work well. Traits and items are on the easier end! PF traits are generally balanced a bit differently (they generally have a higher attribute bonus, approximately +1 net attributes & either a conditional +1 roll bonus or a WAR DIE, while their narrative powers are usually slightly weaker than some of the bonkers world-altering stuff FIST traits and items can have) but there are suggested qualitative attribute-to-attribute equivalences in the book and I don’t think it would be hard to use CHARACTER TRAITS, FACTION TRAITS, and items in the PF book as reference to tweak existing FIST trait/item supplements to fit in the PF balance. I’d love to hear about it if you give it a shot!