well lots of people killed Anders
Yep, I killed the bastard in every single playthrough. I never hesitated once. I was even hoping that there would be an option to kill him the first time before it finally appears. Not even my mage spared his life. I just can't.
I murdered Zevran in almost all my playthroughts, because he was an assassin that tried to kill me and my character didn't see any reason to trust him. Didn't care if I missed his content.
I also praticed the King's justice on Loghain as a Cousland and pretender to the throne at the side of Anora. ( yep, my warden was an ambitious noble, involved into politics and who didn't feel that he was just a random warden doing his job for humanity ) Also I wasn't willing to lose Alistair, a loyal man I could totally trust, a great friend, a brother with some experience as a warden who fighted at my side since the beginning to put an end to the blight for a paranoid man who divided the country and betrayed his king, a threat to the wardens who never believed in them, to the point where he saw them as one of the enemy.
I also always Kill Flemeth, even if she saved my character's life in the tower. Nothing personal against her, she was a threat to my woman, end of story. I always imagine my character thanking her for saving his life with stoicism... just before drawing slowly his sword from his sheath. 
Never offered Isabela to the enemy. why would I do such thing ? I will also never do any compromise with the Qunari. Count on me. I'll do my best to destroy the qun in all my playthroughs.
However, I wouldn't have hesitated to betray Tallis or to kill her, giving the list of the Qunari spies to the Orlesians and Tevinter. I wish I wasn't railroaded to follow her...
Giving Fenris to the mage is close to evil for me. There's absolutely no reason to do such thing... not even as a mage. He could say some things annoying, ( I personally thought what he said was reasonable ) but it is hardly harmful toward anyone.
Nope, I didn't see any reason to be angry against the companions overall. Anyways my characters are hardly perfect paragon people. They live in a ruthless world and they fit to this world. They are all flawed. There could be different reasons why I would act against them, political or moral, or personal. ( My female warden killed Nathaniel Howe for example who tried to kill her, but mostly because she wanted eradicate all the Howe after what they did to her family.
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