I don't see how it's murder when Pharamond wants to die, because he finds the alternative that much worse. It's addressed by Fenris that suicide is a sin, so I can see why Pharamond would have preferred that someone kill him.
As for Anders, the nature of the Chantry controlled Circles is part of the issue for his destruction of the Kirkwall Chantry. For some, his actions are terrorism, plain and simple; for others, he's taking action to abolish the slavery of his people by any means necessary, including killing people who belong to the institution that has control over his people. The circular discussion about this act hasn't really reached any new ground in years, because there is no consensus to be reached among people who have the complete opposite reaction about what Anders did.
I don't see why Pharamond should pay penance when he was doing what he was told, as a tranquil, especially given how compliant we saw the tranquil in Kirkwall.
Or he was merely compelled to say such a thing you know, given the whole demon, blood magic business.
And the circle isn't slavery, doesn't fit any of the criteria, so to me its mere hyperbole of the pro mages, not much else. Said as much to Anders in game
So he can stick to his mass murdering ways, Ultimately it was his politics that dictated him to do it, well that allowing a spirit to posses him, genius.
Because ultimately the choice to do such a thing was up to him, Him following the Divine's will, his choice, Him experimenting with such a thing out in the middle of nowhere with no one to protect the innocent was ultimately on him and the Divine both, but it was by her will that he do it with out Templar escort.
I'd say her blame is greater, but he needed to be punished as well.