You should only be able to put an iten into the toolbar if the item was placed in your melee/gun slot or in the vest/shirt/pants, since its quite difficult to take an item from your backpack without looking at it. Other Ideia is to change the shape of clothes inventory depending on their real pocket position, it would be really interesting to see it in all clothes, but on the backpacks would be the best, making it much more close to reallity. An example of the second mechanic made in photoshop is the first picture:
The third idea is to change the mountain backpack so it has a slot for a small tent (see my next report), a canteen and a fire tripod such as normal camping backpacks in real life. THe third mechanic is displayed as a photo of my real life camping backpack holding a canteen and a small 2 person tent: