This group consists of people who live in tornado, hurricane, flood, wildfire, earthquake or heavy snowfall-prone areas and want to be prepared for possible emergencies. They invest in material for fortifying structures and tools for rebuilding and constructing temporary shelters. While assuming the long-term continuity of society, some may have invested in a custom-built shelter, food, water, medicine, and enough supplies to get by until contact with the rest of the world resumes following a natural emergency.
Of all the supplies they suggest you legally or illegally procure, epinephrine sounds like the biggest stretch. We don't want to burst anyone's bubble, but if you suffer from life-threatening allergic reactions and really think you're going to survive limited food sources and practically nonexistent medical care, we've got a mint-condition fallout shelter to sell you.
Each type you listed (save a couple) will have its uses in a community (group if you will), generally having a small trusted group with each having several skills in the various fields (prepper, homesteader, and survivalist) I believe would be an effective team, though as each group works together would it not be best to ensure that each has overlapping skills in case of injury, death, or other reasoning they can not fulfill their duties?
Gerald Celente, founder of the Trends Research Institute, noted how many modern survivalists deviate from the classic archetype, terming this new style "neo-survivalism"; "you know, the caricature, the guy with the AK-47 heading to the hills with enough ammunition and pork and beans to ride out the storm. This [neo-survivalist] is a very different one from that".
Say you're at work and a terrorist attack occurs. Roads are closed to any and all traffic but you only want to get home - even if that means walking. You may not want to grab your full on family pack in the car or you may not even be able to get to it. But you just want a light kit to get you through. How far is it to get home from wherever you may be? This get home kit should provide for 1-3 nights of traveling on foot till you make it home.