1. Does it work on all heat pads and heat tape?
yes
2. Can I rely on it to stop my snake from getting burned?
not really. you can not set it to a set temperature. its a dial with a probe. the probe with go inside your tub or tank and you set the dial to how ever high you want it. you have to be extemely careful.
3. If you've ever owned one what are the pro's and con's of it?
pros - can use it if youre in a bind but its important you keep a very watchful eye.
con - it can cause temps that are too high and too low

honestly its better to save your money and get a thermostat that you can actually set the temp on.