No flashlights in FAKs is a personal pet peeve of mine, and it never ceases to amaze me that I'm forever advised to remove them whenever I share the contents of my FAKs. A headlamp is best, IMO, but an LED at minimum is in all of mine. Doing first aid in poor light is terrible to impossible, not to mention that it can be helpful in assessing head injuries, and drug-induced reactions.

I think that a FAK should be able to stand alone , apart from a PSK or other gear, not for survival, but for casualty assessment and care. A little light, water, blanket... all essentials to a good kit, IMO, unless it's just a boo boo kit.

It's hard to get those essentials in a pocket sized kit, and frankly, I'd rather go with something more comprehensive when I'm looking at being in a self reliant situation for any amount of time.