Lot's of thoughts..... what happens if you have one of those little small metal pill containers on your keyring and you get pulled over by an eager Police Officer? Technically, because it isn't in the Rx bottle and if you do not have the Rx with you you can be arrested. Seriously, who carries around full Rx pill bottles?
I fly a lot ... A LOT! I scanned my Rx into JPEG or PDF and carry a sized down copy in my shaving kit, have a pic of the Rx on my phone AND keep a USB drive (several) securely stashed with Rx and other emergency contact info. I've never had a problem with TSA but do get flagged often because I have many one-way segments. Most TSA agents aren't bad but a few have been pretty ridiculous, and it's usually in smaller regional airports.
Regarding meds in a "disaster zone" .... I would not be worried about showing proof of an Rx. Look at New Orleans and Katrina... that kind of disaster and looters are out in full-force. Pharmacy and liquor stores will be the first hit (next to milk and bread). You should start preparing now and have a 30 day reserve of everything, meds, water, food... right down to toilet paper. Do not count on the Government to save you ... even FEMA says be prepared to stand on your own for at least 72 hours.
I've done a lot of research on Veterinary meds, in a pinch I would not hesitate to substitute vet anti-antibiotics and have stocked up on several,
Build a kit - Make a plan
http://www.ready.gov/build-a-kit