any visible gun will quickly make you a target. A group may even try to take it with them being totally unarmed.
Your son needs to be skilled with a gun but with call of duty that's not a issue theses days.
making a very effective filter could easily be made using stuff use might already have that along with boiling you could bottle into 1gal or larger jugs and store for X amount of time.
Just build a solar heater and have been insulating the area in which i live. I believe it's going to be a very cold winter with a lot of snow but that's just my guess as i feel we haven't has a bad one in a while.
I dont think the first post really applies to us (USA). Things are much different here then say Europe. Though some of the points were good. But i vbleieve back roads are better then main which will be blocked. Also i think being in the middle of a city if a SHTF situation is worst case unless...