If I was the engineering team, I would be trying to eliminate all these noises. Every single one of these could be engineered away. For example the pops and bangs at a supercharger is the metal shield deforming when heated. Instead, it should have circular ridges stamped into it around the fixing points to let it expand against the springiness of the steel. The clunk noise from brakes could be engineered away by usin…
But for a Model 3 where you need to carefully manage costs or you will either price yourself out of the market (and Tesla is already at the high end of it!) or go bankrupt I think you will have much bigger fish to fry than dealing with such noises.
You also obviously don't understand the engineering decisions - e.g. having the high voltage always on is not possible/allowed. It is a legal requirement because it must be possible to disable the high voltage circuit when doing maintenance on the car - or in the case of an accident. And it needs to switch off the moment the airbags activate, it is not only there for the firemen to turn off.
Also having the high voltage circuit off when the car is parked reduces the risks of fire should anything happen (malfunction, another vehicle crashes into a parked Tesla, etc.)
Manual lever is of no use in such situations. Pyrofuses Tesla already has.