Well, some parts of it are a lot more likely to fail-deadly than others. A commercial power supply that outputs 12V or whatever your servo wants basically can't burn anything.

As for bugs in the control code freezing your pipes? Well, just give the code as much care as you give to driving and you should be fine. ;)

(The serious solution to that is to have a dead simple failsafe controller that switches between on, off and auto, where auto is controlled by your crazy inventions.)