Armorer:
level 1 - damage to armor is halved
level 2 - worn armor protection is increased by 50%, rounding up
Doctor: (requires 1 ironman or 1 tough as nails)
level 1 - medpacks are 25% more potent (small medpacks heal 2.5 + 31.25% max health, large medpacks heal to 125%)
level 2 - medpacks are 50% more potent (small medpacks heal 3 + 37.5% max health, large medpacks heal to 150%)
Force of Will: (requires 1 Finesse)
+3 pushback - player attacks push back as if they did 3 more damage (but with no actual bonus damage)
Ambidexterity:
Dualgunner, but for melee
Digger: (requires Brute level 2)
Can destroy walls with your melee attack, if you hit hard enough (perhaps it also costs the player 1hp each use?)
or
Inner Fire: (requires Berserker)
Melee attacks create 1-range splash damage around attacked square @ half power, which doesn't hurt player. This can possibly destroy walls.
Splash Master: (requires eagle eye 1, finesse 1)
Increase splash damage done to enemies by 50%, decrease splash damage done to the player by 50%
Change intuition levels to range-based (higher levels means longer detection range), rather than levers, powerups, monsters. The current setup means that the third level is far more useful than the first two, and anyone going along this path will take all 3 levels (or otherwise take no levels)