Hey DSF......Sorry to hear you're getting washed out at DL. As far as all the settings, here's the link to the
D80 manual. I'm not the best at explaining all the differences between them so maybe the manual will be of more help than me or another D80 user can chime in. At places like DL, I typically just stay in AF-A since I don't really have to deal with moving subjects using AF-C.
Regarding night time shots, I always use long exposure NR. But, the high ISO NR setting I keep at normal. The D80 inherently handles it very well and there's not usually a need to overcompensate.
As far as the focus area setting, you should be fine with single. I usually use dynamic as that is just my preference. Again, reference the manual for a quicker and better explanation.
Now one you'll really be happy about.......the D80 DOES have a backlight on the LCD top display. If you turn the On/Off switch completely to the right (clockwise) as far as you can, it will illuminate for the specified amount of time in your settings. Custom setting #17 will allow you to set it to stay on for as long as the metering is active. In other words, pressing the shutter half way will activate it.
Good luck and feel better!