You can actually experience it yourself.
Take for instance an ice-skating athlete, when they perform one of those spinning numbers: the g force in one hand is minus the g force in the opposite hand. And it gradually varies through all their body.
What will happen to the human body? With a g force strong enough, it'll get stretched and torn apart.
As long as you are in freefall, you don't feel the acceleration of gravity.
The reason is that you can't feel force directly, you can only feel force when it doesn't act uniformly on all parts of your body.
Example 1: Standing on the ground. Gravity acts uniformly on all parts of your body, but the normal force from the ground acts only on your feet. You ...
If you imagine that in your example the rocket's engine is not initially firing. The rocket and its occupants are falling freely towards the planet below. The occupants will feel weightless, because there is no normal force from any direction.
Now, if you point your rocket's nose down and start the engines, the occupants will fall towards the bottom (or ...
As a scuba diver I know when to do a Valsalva maneuver to equalize pressure on my ears: only when descending from surface during a fast pressure increase. While ascending from the deepth my ears never needed help in equalizing pressure. For the anatomy of the ears see Wikipedia.
The astronauts experienced a fast pressure increase only during the very last ...