1. Other than for legal authorities, who do you stop for?
Given I am trying to get home, I expect to stop for no one, including legal authorities. But admit with my head on a swivel, it will be hard to not provide simple assistance to a child alone and crying. I would attempt to make safe/warm as best I could, as fast as I can, including backtracking them to another group I've past, but ultimately I am moving fast and loose towards my destination.

2. What is your response to those who want what you have?
The likelihood of not having a personal weapon on me is good (Murphys Law), thus I would be looking for a weapon on the move to protect myself. Knowing that I have most likely seen more of the area than those asking (assuming they are stationary) I will provided information on where to find what they want from what I have seen but mine is mine. In the first hours while there could be looting and mayhem, the fear of interaction with a large gang is low, therefore it is simply keeping the head down and moving through/around mob areas.

3. What protocol do you follow with those who want to join you?
Staying solo and mobile is my first priority. However, it would be foolish to not see the benefit of a mutually beneficial pairing. If someone has something that would benefit me getting where I want to go and after going through the same event seems as mental/physically stable as me, then we talk about it.

4. Where do you draw the line between looting and foraging for a resource you decide you need?

I have a strong moral compass but you cannot survive without making critical decisions that you would not consider in a normal day. If after a disaster I come upon a street of cars, I won't take someones car keys if they can drive themselves, but if you're dead and your car is not, I'm gonna see if it turns over. Same with your food, your weapons and your gear. As has been mentioned foraging and looting are separate moral issues (though maybe not criminally). If I need gauze or water or food from an abandoned store and no one gets hurt, great, if I live, I'll make right later. This is a harsh response to a harsh reality, but your goal is to get home as fast as you can, without harming others or yourself.