The intermittent light is due to the brake fluid being at just the right level to trigger the light on and off. The warning light for the brake fluid level being too low is the Parking Brake light coming on. I am just reporting what I read elsewhere. I am not a mechanic and have no personal...
Turning the heat on is like turning on another radiator to the engine. It will take longer to heat up as you are dumping heat into the cab. If you ever overheat in the summer, turn on your heater and that will help cool your engine somewhat.
This guy puts out good videos on YouTube. He has a 2001 Mazda, which is essentially a Ford Ranger.
If you want to use LED's, just purchase the equivalent LED to the incandescent size.