You can drive yourself crazy, not to mention overloading your rig, by trying to carry everything you could possibly need. I don't carry much. A few screwdrivers and pliers. A DVM to test electrical stuff. You're not going to need to rebuild the rig while camping. Just simple nuisance stuff. Anything major can wait until we get home, or in an extreme case can be bought/rented.
You should have the tools to change a tire, and should be tested in the driveway to make sure it all works.