Heya! I'm basically done with the first core part of 3.0 (race/class stuff) and moving to skills. One of the planned skill changes is adding more varied demands and conditions for GM teachers, up to entire mini-quests, and I want to ask for the community's help here as I'm short on ideas. Especially Eksekk, as you did offer to help already. Here's what I have so far:
Melee weapons: have enough expertise with the weapon (i.e. kill X monsters with it, counted from the game start). Probably no need to make unique conditions for each one.
Bow: either the same as above, or a mini-quest to kill two monsters with one double-shot.
Blaster: get eradicated! This skill will grant a small chance to eradicate on hit on GM, so it makes sense.
Unarmed: kill a bounty monster with your bare hands? Kinda weak though.
Dodging: kill a tough monster (a dragon maybe?) without being hit.
Armor skills and Shield: like with weapons, but block a total of X hits while wearing it.
Magic schools: higher skill requirement (12 instead of 10), plus light and dark teachers require commitment to the light/dark path (you can mix light/dark promotions in my mod, but this limitation means you still can't get both GMs in the same game), and the others could require high elemental resistance (fire for Fire, shock for Air etc., maybe AC for Earth). Could make unique demands instead, but no ideas.
Alchemy: brew a rejuvenation potion. I plan to allow brewing potions without the required alchemy skill, with the caveat that the mixture still has a high chance to explode -- 83% for black potions in particular, so this mini-quest is possible but not trivial.
Bodybuilding: go for three days without rest. (Planned GM skill effect is regeneration, so this makes sense.)
Meditation: meditate (rest) on top of Mt. Nighon.
Armsmaster: perhaps kill a monster with each weapon you can wield? Not sure about this.
Perception: find the obelisk treasure!
Stealing: shoplift an expensive enough item, I guess?
Merchant: can just demand 100000 gold for training, ha ha. Or you must be rich enough (like earn a million gold), but this money isn't taken.
Still no ideas: ID Item, Repair, ID Monster, Disarm Traps. Any help is appreciated!