It doesn't make the room bright because it's FCO. FCO isn't good mounted low like that because it's focused downward. As you can see thoguh, FCO doesn't cut sky glow, as the light is reflected off the ground and into the sky as shown here. (if the ceiling was the sky, it'd be lit)
Yep. Just move the socket bracket one hole over and you have a whole new distribution. My M-400 has six socket positions. Only a few are designed for the 400w coated merc that runs in it.