Glad you didn't take the critis bad .
Anyway try to model some planes to receive shadows replacing the ground and others objects of the surroundings, then render everything in passes and start playing in photoshop (in this kind of stuff photoshop it's much more important than any 3d model).
I did a experience just like that some time ago that also need a lot of rework especialy in the shadows that it's to strong and crisp for my taste (but i used sketchup shadows and not the render shadows so can't ask for miracles lol).
anyway here's the pic and the original post if you want to see it
http://forums.sketchucation.com/viewtopic.php?f=81&t=14346
BTW if you have any pose tips for sketchup you could share it would be great (because it's one of the worst thinkgs to try do in sketchup for me).
David