Firstly, WW really needs dual wield for 15% ias. Move speed, Ias, cc, cd LS/LoH is most important to keep fury/hp up. The further u go into Mp the more damage/resist/hp/dodge/armor u will need. The more dmg u have the less LS u need. Ive had a ww barb at 250k base with only 3% LS and no LoH and that has been fine for botting mp5+.
Im doing MP 5 atm with skorn, rend bloodlust, BR Marauders rage, war cry impunity, WotB isanity, Bash punish.
Using 3 reduc passives
NoS, Superstition, ToA
With my gear+BR+punsh running at 67k hp 170k dmg 380k with WotB up.Without wep master ruthless ect ect,
Gear cost about 50mill with couple good drops aswell.
Running about 400k GpH, but at 500 mf+ u make much much more from drops than what u would gold farming mp0 so i dont worry too much bout gph.
Also my build is based mainly about having full fury at the end of every fight so that u can use sprint marathon a LOT so its very quick with 24% move speed aswell.
Hota is good for build aswell but leaves u with no fury for marathon at end of fights. I stack life% once ive got 1k vit
WW is better for low Mp lvls imo.
Hope this helps