Vorathrad: The problem comes in presentation. You cannot present the "purest" form of an emotion.
1) We simply do not know enough about emotions to develop a serious discussion about what the "purest" form of any of them would even look like.
2) They would be utterly incapable of any real interaction. I could make a valid argument suggesting that the "purest form of wisdom" would never utter a single word - because words create limitation - limitation embodies confusion - confusion is not wisdom. The purest form of wisdom could (I suggest would) be completely silent. NOTE: I also believe that a vast array of real world texts on the concept of wisdom would agree with me.
Likewise - the purest form of rage would not be able to speak either. Rage offers no room for discourse. Neither would the purest form of sloth.
I'm not just being argumentative... I know Bioware likely doesn't explore these concepts beyond: "Oh, neat." But I do not believe my opinion is incorrect if the concept of the "purest" of anything is explored.
Ultimately - the "purest" "form" of anything would"look" like all the real world gods. Nothing at all. If a god exists in our reality, and if it is omniscient, omnipresent and omnipotent... otherwise "perfect" - it can have no form the human eye (and human brain) could conceive.
So to... with spirits. They would be inconceivable.
3) Spirits are capable of being "almost" person like. Cole, for example, has simply become a compassionate mortal. There is nothing that can outwardly be pointed to about Cole that says: "He is incapable of being compassionate." any more than someone who defines their life by compassion would be "incapable" of being anything but compassionate.
NOTE: Again, the "Rule of Cool" breaks down any real conversations about these topics. Either 1) Cole is not unique and, at least in theory, all spirits can become "mortal". or 2) Cole was a cool idea... and discussing any sort of consistent concepts about the DA cosmology is ultimately moot.