1. What it is (or at least what it is on my '87) is a silkscreened copper trace stuck in a red lamp holder. I have never seen anything else like it in my limited travels, may be a special order item from the dealer.

2. As speedy mentioned, the gauges all come out from behind. I believe the clear front panel is glued/fused to the cluster housing, I wouldn't try to remove it.

Dunno about (3) or (4), although once I did try to remove the speedo needle without much luck.

My question though, is whether any of the center console units get power through the instrument cluster? Ever since I fiddled around with my cluster awhile back (and replaced the radio), the center console always lights up, regardless of whether the lights are on (or where the dimmer switch is). Can't seem to figure that one out...