Thanks for the thoughts! The placing of Kendra in the first image was one of my many attempts to work on photos that have a lot of space off to one side of the subject. I've often liked many of the photos that I've seen that are done this way and have been working to figure out what works and what doesn't. I can readily see though that with this being a glamour forum, tightly cropped intimate feeling photos are more the desired result. I'll keep working on it, and yes I would agree, the tree does take some of the attention away from the model.
Regarding focus, I do focus directly on the eye closest to me in most cases, and that certainly is what I was attempting to do here. Most of the soft issues that you are seeing here are due to downsizing the image to 800 pixels on the long side before uploading on to the site. I'm not completely sure, but I think the forum downsizes even further resulting in what we get to see above. The second photo was the only one that was slightly out of focus, and was only noticeable when viewing near full size. Even then the soft look is due to camera movement instead of focus due to the slow shutter speed, large f-stop, and lack of flash. 1/60 hand held @ f2.8 non IS lens.
You're probably right about the underexposure on number three as well. I'm still figuring out how to use the histogram when there is so much variance in the scene. For instance, all the black in the tunnel between the model and the end of the tunnel make for a leftsided histogram. More experience with these kinds of scenes I'm sure will help. Thanks again for taking the time to share your thoughts!