Anders is not lying when he points out Tranquilizations are happening frequently and illegally. Karl is proof of that, and Cullen in DAI supports the evidence. Meredith might not be following a Tranquil solution, but she is abusing the ritual.
Then show us. Don't just say it happens. Actually show that people are getting unjustly tranquilizied on a regular basis.
There are accounts of beatings and rape in the Circle. A character encountered named Alain has ambient dialogue that suggests a Templar named Karras is sneaking into his room at night, and any attempt Alain makes at reporting him his ignored.
"Accounts of" implies plurality. And again, show us that this actually happens, outside of ambient dialogue. On one side, you have freak blood mages killing everyone and everything. On the other, you have ambient dialogue mentioning oppression. Which one actually makes an impression on the player and adds +1 insanity to their own factions?
Evelina might succumb to a demon, yet does so because the Templars had tricked her into thinking the orphans she was taking care of would be looked after if she willingly entered the Circle
Mages succumbing to demons or blood magic because of templars, geez this one is new.
and became a demon to defend herself.
Not really an excuse. Becoming a demon has more repercussions than dying, because the demon isn't interested in just acts that you had in mind when you first let it possess you. By becoming a demon or resorting to blood magic due to le crazy templars, there is a high chance you will instead damage more innocents than you otherwise would have.
When we meet Huon, he is deranged. However, his wife mentions that he was never that way before, and we are lead to believe Huon lost his mind because of his time in the Circle.
Or maybe it's a bad plot that is driven by yet another "this mage is crazy cuz templars".
The point of the entire game is to expose that both sides are equally right and wrong.
On one side, you have a never ending stream of blood mages and lunatics endangering both themselves and innocents because they are either performing blood magic or allowing demons to possess them. On the other side, you have implied oppression. We can see that the game failed to expose that both sides are equally right and wrong, simply through making almost every mage a total nutjob and handwaving it as "THE TEMPLARS DID IT!!!", which is neither convincing or an actual excuse.
The ratio of selfish and careless mages when compared to the potential "oppression" of the templars is too high. Even the one mage that should have been represented as undeniably good to present a contrast, Orsino, goes insane, because BioWare wanted two bossfights at the end. If you only played DA2 then you would think that templars are in the right simply because the entire situation was handled so terribly.