poison damage isn't 1/4 by pvp reduction so even with maxed poison resist's poison does quite a bit of damage, even with all

with a 400 poison nova damage,not including -length%, it will basically do 200 damage no matter what

BoneSpirit is one of the best necro skills because it is affected by fcr, can't be reduced or resisted (very well anyway...)
and it homes in on opponents, but back on topic

Yes. Maxing Bone Shield _IS_ a good idea.