yes gf is only partially good on a tweaker barb who won't be specifically dueling other barbarians

windforce is most useful with 40/15% ias or 40/15 max depending if you reach the next shooting break point with 20% or 15% from shael or a jewel

cruel warpike used on merc is best used with 2 ed/ias jewels which will increase its speed, and damage

the attack speed listed by a weapon means NOTHING, its also a very slow conc/bezerk weapon