I like this idea as well. However, I think that stronger creatures can wield the heavier weapons with more ease than weaker creatres. Also, I am not sure if it will promote group travelling on a large basis, as some could carry several weapons in reserve. What I mean is something like this: A person is adventuring, when he comes across a pack of bandits. He shoots arrows( piercing damage, I think) at them, and fells one or two. By then, the bandits are near him, so he reverts to another weapon, say, a spear. And then when they get too close, he gets to a mace or sword, whichever one the bandits are weaker against.
However, the problem with the above would be the time it takes to put away a weapon and draw another, but just dropping something and drawing usually doesn\'t take much time.
As for range, I think that they could be applied to the same as melee weapons and longrange melee weapons. If I am saying this right. Anyway, range weapons could have things like percing damage (arrows/bolts?), blunt (stones), among other things. Just weaker, though, compared to their melee counterparts. I think that flying creatures could have the same rules applied to them as their melee counterparts (about weakenesses/strengths), and be there to encourage archery/magery.