Agree with all of the above regarding spares, tools, etc. Given the amount of work you've done on your car in the last year, you may want to do a series of post-maintenance checks/drives before heading out west.
First check is a few times around the neighborhood, making sure everything works as intended. Listen for noises, and pay close attention to anything that feels "not quite right." Note any odd smells too. If anything goes wrong, you're within walking distance of home. Check for leaks on return and next morning. Fix everything you find.
Second check is 5-10 miles at varying speeds over different road surfaces and types (freeways, city streets, twisties, train crossings, etc.), followed by same drill as above. Again, if anything goes wrong, you're still reasonably close to home.
When you can repeat the 10-miler with no problem, take a couple hours and go for 50-100 miles. Again, make sure everything works. While it seems like this longer test is redundant, this is when some of the intermittent or heat-related things show up--like an "iffy" voltage regulator in my particular case.
Once you can do 100 miles problem free, you should be pretty confident the car is good to go (assuming wear items--alt belt, etc--are in good shape). Not sure how to guard against a catastrophic failure (seals, etc.) other than prayer and/or positive vibes/zenning into the machine.
FWIW, we've used this kind of PMC approach prior to some LONG trips (e.g. VA to Seattle between Christmas and New Year's Day), and so far we've not had a problem.
Hope this helps!
Steve A-