Unfortunately, you are right on many counts. Talking and walking slower project confidence. Being hyper-available does give people the impression you are at their beck and call. And people are shallow so how you dress & whether you fit in matters. I disagree about taking up space, tho. You can sit in a way that is asymmetrical and project relaxation instead of using up others space. My boss used to spread out all over our tiny meeting table--really annoying.