Ok, here we go....
Pretty much anything with a manual transmission can be "pop started." Doesn't matter if it's new or not, I've started my 2000 Ranger that way, my 95 F-150 and even an 89 F-350. The biggest problem with doing that to a gas vehicle is that depending on motor size and compression, you may need more than a short downhill run. And with diesel in the cold, you're going to have a problem where the diesel may be too cold to start without glow plugs or a block warmer.
An EMP attack will likely trash any electronics in a vehicle. Yes, a vehicle is isolated from the ground by the rubber tires, but that will not save it (same as an airplane that is not hardened against EMP will suffer). There are ways to help harden an auto, but without tearing it apart and shielding all of the wiring, something will likely be fried. Best way to save things is to keep a set of tested spares stored in an improvised Faraday Cage. Just putting them in an ammo can or a foil wrapped box is not enough, they need to be properly grounded and shielded. Microwaves are not the best for this (but they could be used to add an extra layer of protection). Microwaves are shielded for radiation but not impenetrable (a properly constructed Faraday Cage is impenetrable).
Gasoline not only has a short shelf life, but it also requires difficult refining and because of the popularity of gasoline driven vehicles, it will likely run out quickly after a major breakdown in society. Diesel has a much longer shelf life and a usable form of diesel could be refined without majorly expensive equipment.
Batteries are a weak spot. Even storing a new battery doesn't mean it will work 10 or 20 years down the road. A gel-cell like the Optima batteries would likely store better than a regular battery though.
Realistically, if the SHTF, banding together in small groups and having a defensible and stocked retreat to run to would be the best way to survive the initial collapse. But you would have to be prepared to bug out BEFORE things can get really bad. At the first sign of trouble, you'd have to go. After the initial collapse, there may end up being a time period where being in a group tied to a fixed location will spell trouble.
Food (especially seeds and the ability to grow your own food) is important. There is usually a 3-6 month supply of food around here and it could probably be reasonably stretched another couple months if needed. It's not enough for a real collapse, but it's enough for any "normal" disasters that may occur.
Currency will likely be precious metals, food, ammo, alcohol, and other such barter items in the event of a collapse. Owning precious metals through a broker (where you don't actually get to hold the precious metal in your hands) will prove useless in a collapse.
I'd say that as far as weapons, a group standard should be maintained and pick useful calibers that are somewhat popular. (Having a .416 Rigby makes for a pretty serious chunk of lead to throw at something but ammo will be beyond scarce in the event of a collapse). AK weapons, AR weapons, 9mm, .40, .45, 12 gauge, 20 gauge, 30-06, .308, .270 will all be "good" choices. Cartridges such as the .220 swift, .222, and a couple others will be relatively useful since they use the same bullet as the .223, but brass and reloading components will disappear after awhile. Muzzleloaders will be useful for a LONG time, but not the "inline" ones, I'm talking the old-school flintlocks. Unfortunately tire wheel weights are not a pure enough lead to use for casting bullets for them, it's too hard of an alloy and will damage the barrel after repeated use. But you would be able to use them to stretch the amount of pure lead you have access to (maybe one ounce of wheel weight to one pound of lead, not much but it gets you an extra bullet or two).
I'll stop there for the moment....