I am a pretty big fan of BPL branded products, but I am not sure that I would buy one of these. To me the GG Gorilla is looking like perfection, and pretty close to your target specs, so I would probably get one from Glen.
I am in full agreement with several others. The cottage pack industry has matured to the point of highly refined products that are satisfying most readily identifiable niches. I don't see anything unique about the BPL design (yet).
But the BPL name has a pretty good reputation, so I can imagine that you will leverage some market share from folks who just think it would be cool to have a BPL pack. Hopefully not at the expense of any of your cottage brethren.
But I can't resist contributing to the voting, so here are my opinions:
1. No hydration sleeve.
2. Shoulder strap pockets would need to bellowed or similar to accept sunglasses, an eTrex GPS, a pocket camera, or similar sized item and have be stretchy material to be useful. If they can't get there, delete them (have to be high cost/volume item anyway).
3. Keep all three outside mesh pockets, but square and lower the side pockets. They are too high to "draw" a water bottle from without removing the pack anyway. Middle pocket needed for wet gear like tarp or poncho. A lacing system would be okay, but I prefer static cord to bungee.
4. Roll-top, roll-top, roll-top.
5. Long torsos (iliac crest).
6. No load lifters without stays.
Other thoughts (mostly for cost containment):
Make the waist belt webbing extra long and let users trim excess to fit (one size trims to fit all).
Could keep the pack bag the same size for all and adjust where shoulder straps attach to it. S, M, and L torso lengths provide decent fit for most users. M and L cover most men.
Daisy chains add flexibility but detract from looks. Most summer packers probably only use exterior tie ons for closed cell pads. If used for snowshoes, crampons, or tents, I wonder if this would really be the pack of choice.
Would be very helpful to know what the suspension system might be. Pad, frame sheet, stays (curved or straight). This affects other decisions.