Other option, be an enlarged giant. They'll only be able to apply inhaled if they enlarge too, or not at all if they're svirf/gnome.
Be an explorer ranger (I really really want to try this out, I remember liking the explorer part of my explorer/bedoiun).
For KO poison there's a couple legacies for warriors, zo buki edge for assassins, shield of flames for invokers.
For healing, there's that pill that can be gambled... cleansing root or something like that.

Granted, I don't really like the rock-paper-scissor logic of CF classes. Every class should have some options against every other class, other than avoiding fights entirely.