Not supposedly, that's a fundamental function of rechargeable batteries, and largely for chemistry. Heat typically increases reactivity, and vice versa.
Warm batteries/room temperature batteries degrade significantly faster when at full charge. And most people keep their batteries at full charge.
Lowering the temperature slows the degradation down.
Yes, I’ve read that but never tried it. If you’re planning on doing another coat, why waste time and water cleaning your brush? If you wrap it in plastic, the paint should stay liquid a couple hours. If you put it in the fridge, supposedly overnight
I don't think it's shelf life, they are supposed to last longer in the device using them. I did it when I was a kid, couldn't say whether or not it worked though. Condensation is a really good point but I never had a problem with it.