I'm not sure if what I feel for Anders is hate. I'm angry with him, certainly, and I'm angry with his writer for making his final quest so transparent. I knew he was going to bomb the Chantry the moment he asked me to help him gather bomb ingredients. I kept waiting for the chance to talk him out of it, especially as he was my Hawke's LI, but I was never given that chance.
In the end, I executed him. I felt I had to for several reasons:
1.) I was working hard to try to resolve the situation before things got out of hand. My own sister was in the Circle after all. I felt that the best chance to bring an acceptable change was to get Elthina to grow a spine and exercise her authority over Meredith. I kept feeling she was on the cusp of doing that ... until Anders blew her up and forced everyone's hand.
2.) Executing Anders might still have backed Meredith down. At this point, as much as I might love Anders, she's my sister and she's trapped and at Meredith's mercy. Anders just openly, defiantly murdered a bunch of people and put my last surviving relative in immediate, mortal danger. Did he not notice how horrible I felt after my own mother was murdered?
So, I executed my LI to try to salvage the situation and save my sister and wound up massacring both the Circle and the Templars anyhow.
That was the last time I romanced Anders. It was just too hopeless feeling for me to want to go back to that, even attempting not to meta-game.
However, I may make a save that spares Anders just to see if he shows up because it would be interesting to see ...