I just did a 10 mile day hike in the North Georgia Mountains (Bartrum's Trail) over the weekend (nice trail, by the way). I am surprised at how very similar my kit was to yours. I used a Gerber Hydration Pack that I bought from Smokey Mountain Knifeworks:
http://www.smkw.com/webapp/eCommerce/pro...&SKU=G110502 liters of water with a 316 cu inch pocket.
First time out with the Gerber, but would rate it as excellent value for the price.
Heat sheet, PSK, para cord, photon light, bic lighter, first aid kit (AMK kit), map, compass, almost exactly the same content as you had.
Differences:
SAK
stuffed a military type poncho in one side pocket.
GPS in other side pocket
More food (ate lunch on the trail)
Did not pack DEET, but did spay down well before hitting the trail (tick season).
The only thing I might add to your kit is a light weight poncho, both as rain gear and shelter.
I guess I would say yours is a good kit, because it is almost exactly the same as mine!
Also, as you noted, in the winter, I will go to a larger pack and pack more stuff, like watch cap, dry socks, gloves, windbreaker.