Improve those dash lights

I have not used these but here's some thoughts:

1...Dimmer. Might be as easy as putting more resistance in series with the dimmer control. Since the "feed" is the tan wire between the dimmer and the inst fuse, you could put more there if the radio / heater lamp are also LED. If not you would have to split up the orange wiring in the fuse panel and find the cluster feed

3...Intermittent. Might be you need to rework the sockets, or consider just figuring a way to solder the LED right to the circuit board traces. this might mean a different type LED, something made for solder in place

I must admit, I never conceived that' I'd live long enough to see such things as LED headlights.

I'm old enough to remember when there WERE NO LEDs of any kind