1: Personally, I'd go to the hardware store and buy a lamp dimmer switch. Really easy to solder onto the wire to the heatlamp.. and you can dim the bulb a bit to create just the right temperature. Dimmer switches are about $5.. a soldering gun is about $8 if you don't have one already. It's really good for a snake to have a temperature gradient.

2: Well, doesn't sound unusual to me.. sometimes snakes move oddly when in stalking mode.