That's a nice, clean ride. I'll second the recommendation to get a rear rack that mounts to the conveniently provided braze-ons rather than the seatpost rack. Then you could get a couple of grocery panniers and load'er up! No backpack needed.

Nice bike, and proofide the bottom and top of the saddle (I found treating the top helped with the slickness) - let it sit overnight and buff the saddle (the leather will pretty much absorb whatever you put on initially).
I tried a trick recommended on these forums, and it has really worked for me (after my initial proofide treatment): Dampen a towel and wring it as dry as possible. fold the towel and drape it over the saddle overnight. Ride. I've only done this once, but the saddle is noticeably more compliant and is beginning to form to my body.