For #1, dont make the controls adjustable, the pilot has to adapt to the plane, not the other way around.(only in game adjustments for axes, no native software)
#2, calculate the difference from the different steering columns to a average joystick and use this values for all.
#3, can't be simulated at the moment, same for all, no advantage for anyone.
#4, buffet can be simulated with head shake and g with increasing tunnel vision.
#5, must be 'Joe Average' for all pilots, in a few years maybe a body scan and a computerized fitness test in the setup.

(With the body scan some pilots i know couldn't fly 109's anymore

)
Just a few ideas, because it is easy to come up with problems, less so with solutions.