CF 2 is just turns on noise reduction for exposures longer than 30 seconds, of which I have never tried yet.
CF 6 just changes exposure increments to 1/2 stop instead of 1/3. I like it that way but it shouldn't really effect photo outcome, just the way I like to use it.
You might just check to see where you have the veiwfinder diopter adjustment set. If you need it very far off center to appear focused for you then you may have a vision issue, and that would certainly certainly make manually focusing correctly difficult.
