By fundamentals do you mean anything else than combat?
Basically I designed it as you said, around consumable items. So you need to use stuff like fire, speed, invisibility, blindness, etc. to combat more powerful enemies. If you play the Keeper then those things are available as spells with timeouts.
Yeah, poison is not very interesting yet, I just added it recently. I guess throwing knives would count as prevention. I'm hesitant to add resistances, because they are just so boring.
I'm planning to add a separate UI element for examining and picking up lying items, so that should solve the "some items" problem.