Also, would this not be possible at 14th level, when you can get the Blood Crow strike power? (assuming you had already taken the Quicken SLA at a previous level to e.g. quicken said bark skin ki power)?
I think you'd have to be level 16.
First of all, because when you take the feat, you choose one SLA to quicken,
"Choose one of the creature's spell-like abilities, subject to the restrictions described in this feat."
there is no text covering "switching" the SLA to quicken.
Secondly, the feat gives minimum Caster Level to based on the spell level of the SLA. In this case, the spell level is 4 for Blood Crow Strike, so the minimum CL is 16.