Gas powered cars catch fire all the time

Fairly unlikely, we engineer things to fail safe.

Even if so we have ways to calculate the power going in and coming out, and if there's an imbalance kill everything, that's how gfci and arc fault breakers work.

If the insulation doesn't insulate, that is a risk indeed. There would probably have to be some detection mechanism for damaged insulation on top of regular maintenance checks. I don't know if some wiring in the insulation could measure the integrity. Maybe if the voltage would oscillate regularly, picking up on the induction of those changes might allow detecting if the shielding is inconsistent before it actually becomes threat? I only have half-remembered bits of an intro course on electrical engineering years ago, so maybe I'm way off.