Here was a thought I picked up from the Ninja AD&D supplement.
Maybe we can do cascading abilities. Abilities where as you learn them, they can automatically combine together for better abilities. I wasn't going for huge benefits yet, and I haven't really gone over the balance issues too much yet.
A monk ability called All-Around Vision. Which basically acts like avoid backstab, but instead of avoiding it, it forces a backstab to just be like a regular attack. However, if you know that and you know kick, instead the monk gets a free kick (no WAIT_STATE penalty) at the backstabber. So a thief sneaking up to stab a monk would get a kick in the gut instead.
Another monk ability called Instant Stand, where if a monk ends up legswept, bashed, or gusted, or otherwise not standing/fighting, they get to stand in 1/2 the time normally (1/2 the WAIT_STATE penalty, and auto stand). However if they know that and springleap, then instead of auto standing, they auto springleap with no WAIT_STATE penalty.
Maybe another ability like 'Stunning touch' which has a very short duration (like 1 tick) but every attack during that time can have a fairly decent chance of slowing their opponent, even if the opponent is IMM_HOLD. And this would cost like 100 mana to do.
I was thinking along the lines of some kind of 'throwing' ability. Call it Hurl. Originally it would let you slam people around the room in combat. Then maybe, only after mastering that, you can learn 'Great Hurl' which will let you toss mobs out of rooms like psi telekinesis.
Other things of this nature would be interesting too, and probably could be expanded into other ideas. Maybe a system can be put in place for this if we want it to become something bigger than just monks.
Let me know what we think, and I'll start percolating ideas on how to do it.