Barrels: They are good as is except for the spring drop rate i think it would be nice if springs dropped more frequently, being just in par with gears.
Medical Crates: More medical supplies, I usually just find a bandage and nothing more. It would be nice to have a decent amount of meds.
Bradley Loot: More high end gear, not only doors and pistols, maybe more tech/trash, I would also make rockets drop somewhat on 1/50 or so *makes sense since Bradley uses heavy ammo.
Heli Loot: Same as Bradley.
Supply Signal: Reduce the double barrel shotgun drop rate.
Scientists: Drop, with a rate of 1 in every 25 or so some tech trash *seems logic since they are scientists, also ammo, not much tho.
NPCs: Good as they are but it would be nice that they dropped more food, water or meds *just as a player would have by scavenging. Would be nice if some dropped food/meds/water, others ammo and gunpowder, others scavenge materials such as pipes, tarps, etc...