The bedside boomer is always loaded and half safety (1911).
One thing to keep in mind with a magazine is, a fully loaded mag has it's follower spring in full compression. Springs prefer to be in the relaxed (extended position) over time. Compressed springs tend to loose extension length and tension.
Far as loaded ammunition, I keep mine in Military surplus sealed, airtight boxes. I've ignited 40 year old ammo that functions just fine.
I guess how many you have loaded depends entirely on planned use and level of paranoia.