Hello wolfpack and welcome to the forum.

Just wanted to jump in here with a few comments.

In my opinion, I would leave the cell phone chargers, and the high visibility vest out of the bag. Based on what I have read, you are preparing for a true SHTF situation. My guess is that cell phone towers will be off line along with electricity. I am also of the opinion that you should adopt the "grey" man mindset when you travel. Don't stand out. Move quietly and get home quickly, hence my thought to leave the vest. I would suspect that in the SHTF situation that you are describing, there are going to be a lot of people who will want what you are carrying in your pack. Might want to think some more about security. Again, just my opinion. I would also throw in a few coffee filters. You can use them to filter out some of the nasties in the water (bugs, mud, etc....) before you use your water purification system.

On a slightly different note. You stated that you are somewhat out of shape. Is it permissible to wear your boots at work? My thoughts are that if you can wear them to and from work you will keep them broken in along with having your feet used to wearing them. Starting a 20 mile trek in new boots just doesn't sound like a terribly good idea. Also, for a little extra exercise, could you add some weight to what you are currently carrying and get off the bus a stop or two earlier so you get a better walk? What I have done in the past when training for a long hike is to take several water bladders and fill them up and toss them in the pack. This gives you the option if you find that something doesn't fit right or you have bit off more than you can chew then you can just dump the water and lighten the pack to finish up.

Best of luck.

LW