Evidence of Venatori influence in Kirkwall's Mage-Templar conflict?

As the title says, is there any evidence in Inquisition of there having been Venatori influence in the growing conflict between Mages and Templars in Kirkwall? Could they have indirectly influenced the events which led to so many mages resorting to blood magic and turning Kirkwall's Circle of Magi into a corrupt institution? 
I'm aware some of the Templar's abusive treatment toward mages was also responsible for the status quo degenerating into a state of chaos, but the fact that the Venatori suddenly emerge in Inquisition as Corypheus' main supporters when we hadn't even heard of them in the past 2 games seems suspicious, to say the least.
We never did learn who gave Anders the idea of blowing up the Chantry. Could it have come from an infiltrated Venatori in the Mage Underground? And could there have been infiltrated agents in Kirkwall, even within the Circle of Magi, responsible for fueling the mages' revolt and teaching them all sorts of forbidden blood magic? I mean, what IS the Mage Underground? And doesn't infiltrating the Underground (as well as other institutions of magic) seem like the easiest way for Tevinter mages, eager to sow chaos in the South, to sabotage the Chantry, the Circles of Magi and make it easier for a future takeover?