That's a monster of a pack, but if it works...

Ditch the cotton pants, shirts, etc and get light nylon zipoffs, wool, synthetics.... Cotton is ideal for creating the perfect conditions for hypothermia - get wet and stay wet.

I would (and always do) take a base layer, midweight, for emergenicies and sleeping in clean clothing, one wicking shirt, either long sleeved and lightweight or short sleeved and I take along a pair of sleeves (originally made for cycling but work great as convenient add ons for a short sleeve). I take a light down jacket and a rain layer. The fleece beanie and some gloves round out the clothing options that work for me down to freezing. No pajamas, extra pants, extra shorts, extra extras... I do take a spare pair of underwear and wash them on a regular schedule as I go along.

You probably want a sun hat in addition to the sunglasses, and sunscreen - you burn easy out there. I also take SPF 30 lip balm. It's easy to dry out up there.

Expect night temps to 20F - I've had light snow in August. Weather depends on topography, not how far out you go - camping in the bottoms near water will always be colder than camping midway up a ridge. Ridge tops or peak tops are dangerous if a storm blows in.