Does it still look 'too light' when mastered to DVD, and do the combing artifacts appear 'when played on a TV with a dvd player'
Mastering to DVD changes to levels quite a bit, and the artifacts you are seeing on the computer *may* be caused by your player. The real test is to put them out to DVD and check them on a TV set.
Also, you are better off maintaining the full greyscale range, and adjusting your TVs down to get black where you want it - otherwise you just get crushed blacks and a loss of detail. (Although some people think at first glance it is a better picture all dark, in the dark scenes you can't see anything)