should he be able to take the feat. part of the feat does nothing becuz he cant cast while using the ragesong anyway. one of my players really wants it and it really wont be necessary for him anyway. ill be counterspelling the magus or druid before i even blink at his spells
He actually can cast while using ragesong. The Skald is explicitly exempt from the limitations to actions that can be taken while raging.
It is, however, unknown whether raging song will count as bardic performance when qualifying for feats. The question came up during the playtest, but no answer was given. We'll have to wait for the ACG for an official answer.