g, that Scott looks quite nice for what you plan to do. I think money spent on a carbon fork and decent mid-range components is well spent. I would strongly suggest sticking with Shimano 105 or its equivalent or better. The stuff is lighter and stronger, and stays "tuned" for quite a bit longer than low-end components. I also think disc brakes - while not necessary - are a nice upgrade.
My only concern regarding this model is the geometry of the pictured set-up. The riding position looks quite agressive for a bike that you plan to use for commuting. It might just be the image, but it looks like the rider would be stretched out a bit, which is goood for going down hills in the forest (and for lowering your wind resistance) but not necessarily necessary or wanted (and certainly less comfortable) if riding on roads to work. That said, it seems from the specs that the handbar stem is adjustable, and perhaps would allow you to adjust it to a less aggressive, more comfortable pitch. I'm not advocating a shopping bicycle with a basket, but at your age comfort should be one of your concerns.
I would also suggest giving a couple a test ride. Maybe even this Cannondale, which has a HeadShok with a convenient lockout. This would be useful if you ever ride on dirt paths, for example.
http://www.cannondale.com/bikes/07/c...model-7BS.html