I dunno how much I would alter Xbow or Melee. I know I've had trouble with Angel of Death quite often. Maybe it's just my lack of knowledge with it's mechanics, but I can never hit the damn target with that skill. I've tried name locking the target and it jumps over them, tried jumping directly in front of it, and sometimes that hits.
Besides that, I think those two trees sync well enough with others. They both use dragon fire oil heavily and can rely on Famine as well, so mixing there is okay. Getting totem avoid from Nightwalker allows an Xbow Nec to get death's fury and/or howling totems to survive with less worry, thus allowing them to avoid RC and spec into death ward for more survivability as an uberskill. I think those two trees are pretty well off.