In regards to the "too dark" issue, that is likely a problem more in regards to the Alabeo™ Tomahawk. If you feel that X-Plane seems to dark in general, go into the "Rendering Options" under settings and increase the gamma from the default "2.2" to something more like "2.6". The simulator must be restarted for this change to take affect.
For the seating positioning, once you press "Shift-9" and use the up/down/left/right keys to adjust the view position accordingly, simply press "Cntrl+[A Number Pad Key]" such as "Cntrl-1" if you are on a Windows Keyboard. This will save the view to the Num Pad mapping. Now, if you go into the sim again, press "1" on the Number Pad (to the right!), or "2" if you pressed Cntrl-2 in the beginning, or 3 if you used Cntrl-3, etc. You can do this and save views up to 10 times because of the 10 available numbers on the Number Pad (0 through 9).
Best of luck!