It occurred to me that maybe at least one wildshape form should be able to hurt hard-skinned creatures(ie: Chosen, Greater Werewolves). By the current ability to hurt one of these, which is none, I would think that at least one creature would be able to defend itself besides the long range creatures. Well just a suggestion since I find it hard that all the creatures in underdark would be unable do any damage towards these creatures.

Er they can easily, just deal more than 10 damage

Chosen only have 10/+1 DR lots of creatures hurt them, bulls strength before you wildshape into a worg and you deal like 1d6+7 damage if I remember right

Creatures grow that protection (DR) so they -can- survive the underdark. It wouldn't have much of a point if creatures left and right could plow through that. Choosen are rather evolved, and they are the hunters of a lot of things, and their resistances reflect that. The same goes for things like stone lizards and dragozhars, as they both have formed protection that gives them a leg up for survivability.

Druids have the magic weapon equivalent in their animal companion + magic fang. It does wonders of course if facing foes in the wilderness, but yes, sadly not much good within the city limits. Plenty of other tricks in the bag though to get over and around things though, druids have an excellent spell set if used correctly.