Answer:
shrugs and grip exercises doesn't use core
Overloading an electrical socket could cause a fuse to blow
Trust you as a practitioner, be open and honest about their emotional and physical well being, have faith in you and know that they are in a safe environment, confide in you anything they do not want their families, friends, partners to know about but which is important to their well being and the baby's.
No, it's because we need to breathe. Your body needs oxygen. Air pressure has little to nothing to do with it as far as I know.