Mucho sympathy for your experience. There are some positives you can take from it though. The next time someone dangles a nice shiny piece of kit in front of you you'll know not to rely on it (snake) without having used it in a combat situation. Once everybody's smiling you can experiment with the new toys to your heart's content. In the case of the snake I suppose half an hour with a cheap cable tester (Behringer, etc.) in would have been the one, but we live and learn.
Also, the bonus of working for peanuts/free is that you always have the nuclear option of "you've had your money's worth, now f*@# off".
Unprofessional I know but sometimes knowing you could if you wanted keeps you positive.
Sounds like you could have done with a simpler system, by the way. Maybe less is more.
Ohm's Law states, "Your PA isn't as powerful as you think it is".