As avid user and abuser of both Leap of Faith and Wind Dance, I think some change to wings is good for game balance. Maybe 9 seconds is a bit much on the timer though. Some of the other suggestions players have made should also be considered.
Some kind of change will make melee more relevent in groups that use Wing-type strategies.
I don't think the dev's issues are only with Boss kiting, but also things like people's ability to solo raids.
How about just an increased timer when in raids as a compromise?