I think that the issue with over the counter drugs is consent, and whether you have the authority or training to give medications to another person that you can't give consent for. For example, I can give them to my kids, but giving them to your kids is risky unless you've given consent for them. I'm a little unclear about what the issue is with sharing the contents of my first aid kit with another adult, however.
The other thread that I read that I really liked (mentioned earlier) is "First Aid - When Help is Delayed" by Tango61. The post and the resulting conversation were very good.
Oh... final thought RE training. The Red Cross, the Boy Scouts, and others got together and rewrote the standards for Wilderness First Aid, and made a course. I've read the course guide, which I highly recommend, but haven't yet had the opportunity to take the course.