The last thing we need is another mediocre pack. So, design light and sturdy.
1) Gossamer Gear uses a "pad pocket" to reduce overall weight and provide good frame support. Skip the contouring. It should contour to the person using it. I would recommend dropping the CCF as a frame sheet and simply adding a similar feature.
2) The hip belt should be wide. But the strapping reinforcement need not me super heavy duty. To pieces of 1/2" or 3/4" light crossgrain will work. Hip pockets are wanted also. These can be incorporated into the existing belt. Clips need to be checked for burrs and sharp edges, of course.
3) The side pouches need to be larger. An inch or so taller, I would guess, at a minimum. I often add my rolled tarp to one side and a fishing rod (in a light plastic tube) to the other. Again, this stiffens the entire pack a bit.
4) The compression straps are useful, but they are really too big for what you are doing. These (again) should be lighter 1/2". I like the loops to thread heavy duty elastic cord through. With cord locks, these maintain a good tension. All tension points, except the belt, should be at 90 degree “locking”.
5) The closure seems a bit weak. Some sort of cover over the top will help to keep things out of the pack and prevent too much water from entering. Less full, it would be better. Again, heavy duty straps?
6) An internal sleeve of light silnylon will work for "flat" stuff and stakes. About 3/4 length of the pack body works. You might consider a size to incorporate a cone unrolled flat as a frame stiffener. I really miss this when it is not present, even though I don't use a bladder. Some people do, though.
7) Several people like a lower ice axe loop. While I don't get out in the winter anymore, it is useful for hauling the pack around.
8) A small pouch should be added for trash. Everyone forgets this. It should be durable enough to handle melted aluminum, plastic, and other bits of trash generated along the trail or picked up as you go.
9) Not real sure about the pouch and pocket material. Make sure it does not snag and catch on anything. Some grabs little sticks, etc after it "fuzzes" from use. I have rough hands after a few days out, some materials will catch on my hands. Not a good choice in that case.
Hardware should be minimized, but you need some sort of torso strap. It only holds the straps on, on a well set-up pack. But they are necessary. Overall the pack should weigh about 1 pound give or take an ounce or two. The material needs to be strong enough to be good with field use, but light enough to not have issues with durability. So, you are right there with weight! Mostly good durability is attention to detail, good sewing, hot knife material edging(melted), accurate placement of all seams. It will likely take 3-4 prototypes to iron out all the details, stress points, usability necessities(nice-essities.)
As always, a few thoughts…