Definetly get acid flask. Stealable from the siorcanna shaman. It scales only with cunning. With 17 cunning it deals about 128 dmg, armor sundering for 3 turns and only a recharge of 2 turns. This will probably be your bread and butter attack for late game.
You definetly want to max cunning, since all of the following consumables scale with it. Usually consumables have a second scaling stat. Leananenstones are your offensive consumable, scaling with willpower. Consider brazenberry ale and conjurers concoctions to buff allies. Both scale with thougness. Bloodiris scales only with cunning. Naptha with cunning and strength. Vulnarys scale with cunning and presence. And of course Ley-crystal grenades, but though luck getting your hands on those.
Focus your stats on cunning and toughness. The third stat is up to you. Willpower for leanenstones, agility for speed. Maybe even presence for the leadership. I would dumb strength, since it only boosts Naptha.
Edit: Since the removal of resolve, winterstems, wyldsap and wyvern venom are bugged. Avoid those. I don't know, if they are fixed already.
Edit 2: Grease is better than crackle powder. Does not need a ranged weapon, companions benefit from the fire weakness and still fits the roleplay.
Edit 3: Lyric can be your Labratory assistant and advanced biological missile. Heat weapon, since you need a handy way to heat your ingredients and totally not to commit warcrimes against armored foes (hence heat WEAPON).
Edit 4: Thieves smoke bomb. Shatterstrike, stealable from effigie archers. Reflavour it as throwing empty bottles at your enemie. Also the shatter spell. It's just a very big bottle. Wyvern sting for poisenend projectiles.