Cramp is an interesting one. I've never had cramp on the bike and I don't sweat much so I wonder if they are related?
Purely anecdotal I know, but I don't sweat much either (unless it's really baking hot), and I often get killer cramp if I'm giving it beans on a three-hour-plus ride. I suspect it's because I spent most of my twenties sat on my arse in front of computers, and have only started to put some miles in over the past couple of years. Stretching definitely helps, I can feel my legs going a bit crampy after a ride if I don't give them a good stretch out.