Is there math out there for stats?

[Sevyrr]

Skill speed and spell speed affect your cooldowns and skill casting time, attackspeed in my opinion affects only skill casting time, so skillspeed/spellspeed should be better.

From my understanding of weaponskills and the effects of the Arrow buff via Astrologians, attack-speed effects the skill cooldown time, and not the skill cast time.
Experience of the Arrow as a Caster eludes me, so I can't say how it effects cast-times.
Skill- and spell-speed, however, effect both casting and cooldown times, although in a less direct manner: similar to how "accuracy" and "chance to hit" work, skill-and spell-speed are converted to a hidden, relative-to-level, "attack-speed" statistic, that determines the effects.
As such, a buff to attack-speed is a direct buff to that effect, and a buff to skill-/spell-speed buffs the relative gain. (IE:- Attack-speed buff has greater effect than Skill-/Spell-speed buff).