Bow/Xbow speeds

They were calculated from the tick counts transmitted to the server when you use skills.

There's probably an indicator in the data somewhere regarding the skill's interaction with weapon speed, because it isn't a uniform increase/decrease even within the same skill, let alone between different skills.

My guess is that they just modify the delay of the skill by however many ms based on weapon speed. Maybe there are different classes of modification too, as some skills are obviously different from the norm.