my BS is Str/Int built and have been that way ever since i found out how lazy I can be tab-f1'ing in dp's. Ofc I have str for melee dmg and have Int for keeping all toggles on as well as might of underworld if i have mage pets. Usual thing i find in a fast dp is that my mp wont go down even w/o using mp pots/food. Normally sometimes in slow ks dp's I'm forced to use dirk tornado and deplete MP too quickly so it depends. I generally never need vit (other than for running through PP/sanc) at times I will out aggro tanks but not long enough that it kills me. This is my built for BS, I dont farm on her (yet) since she's my pet leveler slave. I tried a few times as mage built but gotten too multitasking in DSing, Fa-spamming, and remembering to have pets attack because E6 use of /petattack hotkey only made selected petattack and not both of them. Made it easier for the /attackwithpet hotkey when melee build which made me the lazy BS I am.
That's my opinion on the melee BS, hope this helps Nys.