Nikon D200 and Adobe Camera RAW (ACR)

[DocSmith]

I've recently sold my soul and entered the world of stock photography. I've been accepted by four companies and I'm getting some downloads, so things are going OK. But - I have had some images rejected because of noise, fringing, and artifacts at 100% view. Now, these images are the same that sell well at art shows and local galleries, so there is nothing wrong with them in print form. The problem arises when they are sent for inspection and reviewed as actual pixels. So, I'm going back to basics and really examining my workflow habits and questioning some thngs I've taken for granted since I started shootng 100% digital in 2004. In addition to actually reading some user manuals, I'd like to ask some basic questions and get some opinions from my esteemed collegues on this site.

I have a Nikon D200 (10.2MP) as my primary camera and I shoot in RAW format at 100 ISO. The resulting files are 16MB or slightly less with dimensions of 3872 x 2592 px and 16.1" x 10.8" at a resolution of 240ppi with a bit depth of 16. I had always assumed the D200 to produce 300ppi. When I examine my ACR settings, I found them to be 300ppi with a bit depth of 8. I assume that this makes no difference regarding noise, so should I leave them as is or change them to 16 and 240?

I go to a lot of trouble determining exposure when I shoot. I usually shoot in aperture priority or manual and I use a light meter and Photovison target to adjust exposure. I white balance for each series of shots and I include a Gretag-McBeth colorchart as the first image when I can for color balance. Problem is, when I open the images in Bridge/ACR they invariably look very underexposed and low in contrast until I apply automatic or preset adjustments, after which they are fine. Why don't they look better right out of the camera?

More later,
Doc