Mark

Ok, "Quickdraw" it is.

Buying up your initiative modifier is fine, I'll add that. -Improve Initiative.

Stamina is good. -Maybe a different name. Resilience? That sounds more on point. Maybe we should just call it "Bruce Willis".

I like the idea of giving up attacks for a better initiative, but I really want players to decide what to do at their initiative and not before. -The lack of declared-casting is for this reason. Maybe instead, a character could take an initiative penalty to increase one on-hand hit roll. Therefore, this can be decided at his initiative, and if he changes his action when the new initiative arrives, that's fine too. It needs to be very simple however, to minimize initiative meddling. How about this?:

Pause and Study (16 skill pts.): Further delay your initiative by -6 for a +2 'to-hit' one opponent for this round of attacks.

(I think the DM shouldn't announce NPC initiatives until they act to keep players guessing.)

Stunning blow is great. It could be played just as Greatstrike.

Yeah, archery abilities could be good.

Harkumen are on the brink. No rush.