Bahbee;

You shouldn't have to make a second, darker background for your panel. At least, I've never had to. Your background will look like you want it during the day, but it'll darken up during the night just by the lack of ambiant light. When you flip the panel light switch, it should light up normally.

For your second question, there's a thread of messages on that subject that was posted a couple of days ago, here. But, it was determined that the effect of landing lights that are visible on the runway in front of you is hardcoded into the aircraft. It was said that you could not add this effect if your aircraft doesn't have it. I might be wrong, but I think this is a specific effect made in GMAX.

Hope that helps.