Calpernia 100%
She is Cory's saving grace, to a point. She makes him more than some cackling Tevinter Magister hell bent on becoming a God for...reasons. I also think this fits well with what BW is trying to do in DAI by introducing Dorian to the fold. We've already got the "Tevinter Magisters are evilz" exterme from DA2. Now it's time to show a different side of that coin. Showing one Tevinter noble who isn't crazy isn't enough to showcase that. I needed more than just one good Tevinter, but something showing that they are human with all the flaws that come with it. So I consider Calpernia to be a good addition to that other side which actually gives Cory a bit more depth as well.
Yes they are. The game even says so by pointing out that Samson manages to retain himself unlike the others. Sure they have peeks of themselves inside...just like those who were indoctrinated by the Reapers, but they are not 100% there.
The line between controlled and "free" is very blurred in the case of the Red Templars. I don't think we can say definitively how much their service to Corypheus was due to mind control and how much it was due to their own choices.
Excerpt from the journal of a red templar:
Writing has become difficult. There is a sharp pain in my hands when I move them, like shards of glass in my knuckles. When I look in the mirror, I don't recognize myself. I remember when Lieutenant Erasmus got this way. He looked like a living corpse, his complexion a facsimile of the blush of life. Instead of blood, it was pulsing red lyrium. It killed him and kept him alive at the same time.
I don't want this anymore. It gave me power, but it goes against everything I was taught. Sometimes I am swept along with the fervor, but in quiet, I remember what I was, and what I believed.
Some say Imshael can cure us. He can pull the red lyrium from our bodies, if we ask him. But there's a price. No price would be too high. I just want to be myself again.
For example here this red templar notes that he/she feels caught up in the fanaticism sometimes, is that psychology or the influence of red lyrium (and how can we know?), yet he/she also seems to be contemplating betrayal and removal of the red lyrium.
It seems a far cry from indoctrination which was far more absolute, I only recall people trying to escape indoctrination by killing themselves and that was only for the supremely strong willed (and with Shepard's influence of course).