"HELP" Power brakes very touchy

You said;
"I have tried adjusting that rod in both directions but no help there as I discovered it only adjusts the height of the pedal. ."
This is not exactly correct. Yes it adjusts the height but that is NOT it's primary function. The end you cannot see is supposed to be seated in the control valve, and the control valve has to be in the fully closed position with the pedal parked.
When you push on the pedal, that rod is supposed to open the control valve, which then allows atmospheric air to enter the power-chamber. the backside of the chamber has been evacuated, by intake vacuum, and so the air introduced into the power chamber can do the work of applying the brakes for you.
As soon as you stop lowering the pedal, the control valve is supposed to close and hold the diaphragm in place. When you release the pedal, the control valve closes the atmospheric port and opens the dump port, so the pedal can be returned to it's parking position, by a brig return spring.
Now, if the control valve is already boosting, because the control rod has been adjusted too long, then when you step on the pedal, boost will be instantaneous and more than you were expecting, and is now difficult to modulate. So then

IF
The pushrod from the booster to the brake pedal has been adjusted back and forth, with no change, and, the pedal has returned to it's parking spot, at the uppermost limit of travel;
THEN
Either,
>the booster is wrong for the application, or
>the control valve inside the booster is not working properly/possibly broken


EDITED for clarity, read it again.