if you have too much dps in t7 it will throw off your voices & shrieks anyway.
my group actually had to lower our DPS and me (the kiter) basically stopped dpsing and just focused on kiting except when I'd throw a few DOTs on the ads.
T6 and T7 are really unfavorable for a black mage (which is also why I switched to smn to begin with) but you should be able to shine in T8 =)