Unless I am missing something, you cannot use any other skill whatsoever while in Profane Veil – you cannot channel PV and use another skill.
Thus, all of the modifiers in the PV tree apply only to the damage of PV itself (not other skills you might use when in PV, as I had sadly first thought).
So then what is the point of the Seance node? Am I supposed to summon spirits and then quickly enter the veil?
Alright, thanks. I guess I am finding PV much less exciting than I thought I would.