Good points. Everyone plays the game their own way, so obviously some people are going to like different characters. But for the sake of discussion since you ended on a comparison between the body count that Isabella and Anders racked up, let me offer this. It is true that Isabella caused the Qunari uprising by stealing their sacred book. Had she done something very unpirate-like and took responsibilities for her actions by fessing up and returning the book, the whole Qunari attack wouldn't have happened. I'll grant you that.Faerillis said:Big Snip
However, by that logic, Anders is responsible for countless more deaths. True, Isabella's actions caused many to die in Kirkwall...but Anders sparked a civil war that has (according to the ending cinematic of DA 2) engulfed the entire world. The blood of everyone that dies in this magic civil war is on Anders' hand.
My first playthrough of the game I was like you, Anders was one of my favorite characters because I liked both him AND Justice in Awakening. That, and he was the healer, so definitely a handy fellow to keep around . That said however, just like you I was completely drawn in and when the church kerploded, I was staring jaw-dropped at the screen just think. "Dear god Anders....what the FUCK have you done?!" And, just like you, I couldn't stand such a betrayal of trust (since like you said: you help him make all the preparations for his magic bomb). So yeah, I executed him as well.
As to the point about blood magic, that's where I think things get a little confusing. It was my understanding based on what is learned in DAO that Blood Magic can only be taught/acquired by dealing with demons. While it's true, the magic itself isn't inherently evil, it is the fact that you must consort with demons in order to use it that makes it a big no-no. Look at what happens at the end of Merrill's story. No matter what, you have to kill her beloved keeper. And if you don't play your cards right, you'll end up having to slaughter her entire clan...all because she needed blood magic to fix the evil mirror and she had to make a deal with a demon in order to do it. Case in point: when you fight Orsino, he confesses that he's never used blood magic until that very moment...and what happens? He turns into a frickin' demon/abomination.
I'll admit that they never clearly and officially say that you must make a pact with a demon in order to use blood magic (though that is the only way The Warden, if a mage, can unlock the Blood Mage specialization), but evidence has shown that where there is blood magic there are often demons. Look what happens in Redcliff, and The Circle Tower in Fereldin, and that haunted orphanage in the Denerim Elven Alienage, and hell, even the death of Hawke's mother.
So yes, Blood Magic, like all magic, is just another tool for a mage to use. However when you think of all the magical attrocities that have occured, more often than not: Blood Magic is involved.
That aside, it's also forbidden because blood magic doesn't use magic/mana...it uses life force.
That said though, yes, in both DAO and DA2, my main characters (when mages) ALWAYS use blood magic because it's so powerful. :3