Good info, thanks. Yes, I think that in my initial reading of your post(this happens when I am reading my iPad and waiting forever for pages to load) I got tunnel vision and didn't process that you were talking everyday carry/preparedness and so on. Sorry about that.
I want to take more courses on first aid/first responder type skills, so your questions are relevant. In answer, I currently carry very little. Since I commute, anything I put in the car is inaccessible, and what is at work could be of limited use(because it all gets looted and not replenished often. It is so bad that the admins for my group by 1,000 pill bottles of advil, midol, and aspirin since the first aid kits never have them.) I'd love to get one of those wilderness trauma/medical kits if I knew how to use it, but like I said, I probably couldn't carry it with me, so it would be of limited use at least on weekdays.
With respect to whether or not I would, the couple of times I have been tested, I have helped the person in need. I guess I am a good person or something, because I don't really think about it. That said, it is funny to see how people change when in a group. When you are in a group(say, at the train station) everyone seems to think someone else is going to help, and depending on the situation I will if I think I can. It's very bizarre to see someone get hit by a car 100 yards from the train station and almost all the people look at their watches(train's coming in 3 minutes) and keep walking. I stop to help, yell at a couple of people to call 911, run through the checklist, and in 5 minutes am being asked to step away my the police. (The person was mostly shaken up.)
That said, my recent experience has completely soured me on assisting almost anyone in any capacity. Simply consider that any time you help someone, from a close family member to a complete stranger, you open yourself up to the possibility of unlimited liability should that person decide to sue you. Your preparedness program should include not only beans and band-aids, but financial and legal preparedness as well. To the extent that you have any wealth, and are exposing yourself to other people, you are obliged to protect what you have.