A few hour poker tournament can be exhausting, especially pre-bubble during the grind. If I had to try to act like someone I'm not during that time, it could be downright grueling. So I just be myself. Since it's just not in my personality to trash talk, I don't do it. If it works for you, go for it.
Also, I think the more you talk, the more you reveal. Moreover, I think it's better to blend in than to stand out. The more people you annoy the more people who will want you out of the game. Then again, you could use that to your advantage as well. So just be yourself and work with it accordingly.