Your better off asking support your specific questions when it comes to the TOS, as we're just customers, but...
You should monitor the content of your site, since it is you that's responsible for it. That's true with all hosts.
Remember that YouTube pretty much has a ton of money for lawyers when they need them, so you don't want to get sloppy.
Basically, if it's legal, it's okay with Dreamhost. If I had a video upload site, I'd probably moderate it and approve/reject each one. If someone uploads an episode of Seinfeld, or a camcorder movie bootleg, it's probably not theirs to give away.
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