I like the idea, expense might be an issue for some. Complete kits can get expensive fast. A good bag and good gear is a must. I am NO expert in the area but I try to get as much first aid training as a I can, especial on the wilderness and combat end of things.
I would look to the tactical side of medic care for some ideas as well, both in treatment and supplies. I am becoming a BIG fan of MOLLE pouches and accessories. Things like asherman chest seal, CAT tourniquets, Israeli Field Dressings, Hemclot, kerlix, BFG Trauma NOW pouch, Maxpedition Active Shooter Bag, ect
I would also distinguish between a boo boo kit and a trauma/IFAK kit. For us we have three distinct kits. Truck/Home kits that is very complete, large, and virtually identical. Three day kits that move around for the car, camping, boat ect. Basically a boo boo kit. And we also have a range/trauma kit that has easy access and moves around as well.
Our home and truck kits are hard cased where as our three day kits and trauma kits are in packs or cases.