Fair points. But I am sure they have something in their manual or Terms that says not responsible for damage to vinyl etc. I think the "safety" is for the vinyl, not my home wiring or even for a fire risk in the machine. A short circuit in this case is not a hazard since we aren't talking service amps coming into your house, this is more or less a bypass of the thermistor so it doesn't trip the shutoff.
If the machine gets bricked from my tinkering with it (at their direction) it's still under warranty which they assured me in writing. I'm sure that's worth about as much as the paper it's printed on but I have entered into the agreement in good faith and that's about all I can expect them to honor at the end of the day.
It is tough for me to play devil's advocate against myself on this too. I am rightly pissed off that I have had to do this much back and forth over their failing. I'm just doing the best I can to try and save my money for return shipping until it's absolutely necessary.
If anyone has any advice on how to avoid paying return shipping I'm all ears.