Linksys Wireless Router :: WRT54G What Is Priority Of A Device That Is Not Listed At All

I recently have been reading into QOS and have been fiddling with it on my Linksys WRT54G router. But there are a few things that seem limiting (at least on this version) so I have some questions.I live in a house with three other roommates all sharing the same internet connection. We don't have a bandwidth limit, so I don't care how much they're downloading. When I want to watch Netflix when they're all on the internet however, either my movies will come up in low quality, or will be interrupted.Under the Device Priority I put in my MAC address and set my priority to high. My first question is, what is the priority of a device that is not listed at all? There's only room for two devices so I can't put all three of my roommates in. I would assume their priority would automatically be the lowest.
 
I wanted to set certain common ports to be at a high priority. So far I just have port 53 for DNS entered with the highest priority, while my computer is set to high. Would this mean any computer making a DNS request would have a higher priority than my computer making a non-DNS query? I would like DNS to be a higher priority than myself streaming video.Finally, are there are ports that streaming video commonly use? I know there are ports for Netflix but I was also thinking of other Flash/HTML5 videos I might come across. Or do they tend to just use port 80?