Digimark:

I use the following categories, derived from the rule of threes.

Medical
Shelter
Fire
Signals
Water
Food
Tools

So I sorted your lists into those categories, and did a casual examination. The few things I'd suggest are:

In the shelter group, you could add a fleece or velour sleeping bag or blanket. Just seems right in the vehicle for a multitude of applications, including treating accident victims for shock. (Make it cheapish so you won't mind giving it away to someone.)

Also in the shelter group, I was thinking about having to hunker down under your tarp in the winter. (I live in Florida, so I'm not too concerned about cold weather.) You could add a couple of closed cell foam pads to keep you warm underneath. You could cut them to size and store them flat. They can also be used to improvise splints.

In the Tools group, I think you'd enjoy having a Frosts or Mora fixed blade knife. They're inexpensive, and will do most anything that a more expensive knife will do.

I carry a roll of mason's twine in my trunk for the multitude of odd jobs that don't warrant paracord.

Aside from those ideas, nothing seemed missing from your lineup.

I would go ahead and get a pot of some kind for cooking, boiling water, digging, fetching water, etc. If you get an MSR Stowaway pot, you'll have a locking container for part of your kit, plus a pot with its own handle.

For stoves, I really like Trangias -- of any model. You can get a similar deal in used Swedish army gear, but just now I'd avoid the used ones available at Sportsman's Guide. I've tried my luck several times, and they're always very heavily used and generally damaged.

Means you have to carry a small supply of alcohol (methanol or ethanol) with you, but for convenience and a clean fire, it's hard to beat.

None of these suggestions are especially well thought out -- just my casual ovservations and ideas.

Bear