I guess we are getting stuck on words now ^^
Sexualization in sense I'm speaking here is mostly negative and it's sexualization of something that doesn't need to be sexualized and isn't already made to be sexy in way someone wants to change her/him to be (it can be still sexy depending on personal attraction). Giving Cassandra bikini armor would sexualize her in way that is negative, it would go against her as character (I think she would feel humiliated instead of feeling strong and sexy in that taking accord her personality) and would break art-style of Dragon Age as well. I think this is the kind of sexualisation that I'm speaking at least ^^
When I think sexualization as something positive, to me it's designing sexy characters who are in top of their attractiviness like Isabela, Zevran or Selina Kyle (Catwoman). Still not going ridiculously sexy unless that's whole point of the art of the game or someone other media (and hopefully implied to both genders) in terms of making her outfit still reasonable and not looking like fetish-wear 
I hope I'm making some kind of sense here on my view 
You're making sense about what you want to say, but the content of what you want to say and do say is muddy at best.
Your point is utterly based on personal taste and opinion, such as "doesn't need to be sexualised"-says who? And does it "need to not be sexualised" instead?-Says who again? "Going against character" Really? You legitimately think personality has a bearing on clothing? There are clothes that reflect thinking types or mindsets? I really don't agree with that and its implications.
The whole concept of positive/negative sexualisation can't appear to seem as anything other than subjective and taste-based, from what I've seen so far.
The only thing that could make sense is your "would break art-style of Dragon Age", since there are obviously stylistic trends in DA and suddenly having a character in outfits like Terra online would be..."not in agreement with the current fashion style of the world" , to put it mildly, but then again, even in real life there are exceptions and new trends or individuals who just don't care and do their own thing, so that wouldn't be an actual issue either.
Edit, I originally thought I wouldn't comment on that, but the post before me that got typed while I was still writing this and I changed my opinion after seeing it. It's obviously not directed at Panda, it's more of a general statement, it's not even addressed at BeefheartSpud.
Some posters here really give out a bizarre "wah, wah, plethora of titillation can't be a valid source of entertainment in video games" bitterness vibe. It's really weird and really sad. People should obviously voice their distaste and ask for things to be as they want but when they try to say that some sort of aesthetics are "superior" to others or that some aesthetics are "questionable" it gets really ludicrous. Especially when we reach levels of wanting things to be one way, not because of personal enjoyment but to spite others.
Obviously, the same goes to people who think that lack of titillation is an issue.