TheKomandorShepard wrote...
1.I bet you did something di*** for own pleasure and just now you just don't see that and no im not god. 
2.And what is necessary evil you aren't forced to do that and you don't have to neither you can say that was necessary evil because you cant say what would happen if you took other options so necessary evil is only matter of your perspective and try to justify goal.
example you may warden can use that as justification to reach goal but was it necessary nope...
3.As i said im trying to survive and many mages caused huge destruction i prefer my safety is that necessary evil nope or perhaps can i call that way yes...
And what is wrong with other beings in that world and why conscience makes us better or even difference?
1. No, I did not do anything bad for my own pleasure, and I don't know how you can say that with certainty.
2. Necessary Evil means doing something morally objectionable for the greater good (ends justifying the means and all that) and you aren't forced to do anything, you could sit in front of a TV all day in a semi-conscious state eating cheetos.
3.Mages are the sole reason for every major disaster in Thedas, but that still does not justify killing everyone, Germans caused unquantifiable (hyperbole) levels of destruction through out the world, so what would have been your solution after the end of WW II , kill every German?
Conscience makes us different , that's a no brainer, no other species have conscience, we do, that's why we are different.
In terms of why it makes us better
Do you know that we are the only species on Earth that observe 'Shark Week', Sharks don't observe 'Shark week' but we do, that's how awesome we are.