I strongly discourage storing gasoline inside vehicles or structures – the risk from explosive vapors, in my opinion, outweighs the benefits. I would suggest rather to keep your fuel tank(s) as full as you can and plan on limited use in the event of a crisis. Or, as I was fortunate to be able to do, drive a diesel vehicle, get a diesel generator (there are small/relatively affordable ones) and store fuel outside in a 500 gal tank!
About the rice: It is my understanding that parboiled (converted rice) stores and cooks like white rice, but has similar flavor and nutrition to brown rice.
I had heard that Doxycycline (and other -cyclines) are one of the few medications that become toxic when they age (as opposed to just becoming less effective). If so, it would be important to monitor expiration dates and replace as required.