I appreciate the honesty, it will only help. I hardly ever solicit outside criticism, and I think my work suffers as a result. So be as honest as you need to be!
These were rendered in Max/vray.
I agree with much of what you're saying... the lighting does look a little dark and flat... I was sort of going for an image where it's sort of dark outside and the lights are somewhat dim inside. These were used for marketing purposes (on a small budget) and thus, needed to explain the design of the house in a couple of images. So throughout the process I kept making certain areas brighter so people would be able to see what was going on.
For the floor, I used the multitexture floor generator from CG Source, which is very cool... and the flooring itself is pre-engineered, all the same length. I guess they could randomize the pattern during installation but we didn't get into that. The rug needs help, yes.
I definitely need to fix the view through the windows... the dark portion at the bottom is in the background image... I tried to blend it in with trees but the trees are too light.
White window frames and the orange wall are the architect's decisions, so they are what they are.
Thanks again for the comments so far, I definitely appreciate the help.