Great work man. Here are some random thoughts and you may have this stuff already:

Water and tough containers. The milk jug containers don't even last a couple months in my Jeep, they leak. Maybe it's just the desert sun in my area.

Adding more batteries, I see your GPS there.

Swampping out the iodine based water treatment for some Aqua Mira. Tastes much better http://www.backpackinglight.com/cgi-bin/backpackinglight/aquamira_mcnett.html.

A couple of quality Hefty garbase bags are nice to have for shealter or protecting gear against water. You do have the emergency ponchos though.

Think about putting everything in ziploc bags especially the GPS (looks like you have some there can't tell).

I have not found a saw like that that actually stands up to abuse. If you have tried that one and it works, let me know who makes it.

Maps of the area you would most likely be in.

I have found a maglite to be more useful than the OD angle lights. Maybe carry more batteries and spare bulbs for the maglite and ditch the other one? Or carry a smaller LED flashlight.

Prepare the BOB's for the family as well once you get your stuff dialed in.

Some quarters and some cash. Maybe a calling card. Cell phone which you probably carry anyway.

Walkabout radios for vehicle to vehicle and person to person comm within a reasonalble distance.

Hats for everyone. Bandannas are awesome. A big deal here in AZ for sun protecion. Sunblock for the little one's?

Toilet paper and a camp towel.

I use aluminum pots for cooking. I have 3 of them. You can store gear in them while you are not using them to maximize space usage.