I should add this tidbit: I am looking for a remote site to build a bug out casa. If a financial breakdown was to happen, I would get out of town... Roughly 2-3hr south of Denver. I was wonder about more advanced med equipment bc if you are so far away from a medical facility you have to be able to stabilize The causality for hours. When I worked in Africa our med plan was 8 hrs. That's why I had to take a live tissue TCCC course. It's just a sizable chunk of $$$$ and the Darwinism side of me believes only the strong survive. So if someone needs a AED or does have spinal trauma, are they just shit out of luck?
The incidents I have been on from Mass Casualties to NOLA/Katrina vary a great deal. Knowledge is a good start which you have and are continuing to acquire. There are some good books out there for what you are looking at - Conflict and Catastrophe Medicine, Improvised Medicine, and Survival Medicine Handbook are a couple that I have.
Everything you have asked about requires a hospital or higher level medical care at some point. So for the most part yeah they are SOL. Same thing for IV's for bleeding out, people seem to think they are a cure, but if you are dumping fluids into a patient who is bleeding, they need surgery. There are few things we can fix in the field. In true SHTF then prevention is the best thing you can do cause resources (ambulance, hospital, etc.) are gone for after the fact. As you said Darwinism.
Personally I have not put much effort into this because of these issues. It is just not worth it to me right now to put my money into this. If you have the money to spend on it, I say go ahead. Just make sure you are squared away on other things. Just understand for most things all you will be doing is prolonging the problem, not fixing it. Under some situations this may be fine, but not all.
for the most part i agree with you, except on the fluids case. certainly if they have major trauma or internal bleeding there isn't much a person with meager supplies can do. but an IV can be life saving in cases of external damage that can be easily repaired with common sense and some suturing. it just depends when you find the person and how long they have been losing fluids.
AED's aren't even close to worth it. great, you bring a person out of cardiac arrest, now what? its not like a person who just experienced cardiac arrest just jumps up and is good to go, they need to get to a hospital and be monitored not to mention you need to diagnose specifically what was the issue. if they had some form of heart attack there isn't anything you can really do for them, they need to be in a hospital and are going to need both acute and long term medications you won't have access to.
besides basic med supplies, and POSSIBLY antibiotics if you know what you are doing and can find a fairly easy way to access them, spending tons of money of medical things is a waste. if things get that bad rule number 1 is going to be don't get seriously injured. might as well put it into food, water, ammo, arms, and if possible setting up your house to be better protected and sustaining.