no nozzle = explosion
must be some measure of nozzle efficiency/effectiveness but no clear idea of it.
not the surface but the hole as it were.
To accelerate the body a force must act on the body. Application of 'control surfaces' often simplifies the maths but can mislead. The body doesn't 'know' what some parcel of ejected air is doing but remote parts of the air affect the air next to it which can be tracked back to the air next to the body and then to the body itself. Continuity. So in terms of whats happening at the hole, specifically 'no' but everything is connected to something else !.
On reflection, can't see that helping !