No. A driver drives the car. Unless it’s a self-driving car.

Spark plug normally comes with the torque information. Use that. It maybe angle tighten method. That only applies the first time it’s installed.

Just going by feeling is common too.

I’ve never done this on a Volvo but if nothing else works you’ll have to fully remove the door panel with the door closed and then physically break (by drilling etc.) the door latch until you can just move or remove the parts inside of it and door will be able to open.

Taking the seat out is probably the first step if you go for this.

Check that there’s brake fluid in the reservoir. Or much better have the shop inspect their work. Seems like they forgot something.

Them telling not to worry about this seems wrong. Either I’m misunderstanding something, or you misunderstood, or it’s a bad shop.