If I set up a web site featuring videos or audio clips from fellow Hive members (especially those with regular vlogs or podcasts), I would earn HIVE as a host and as a consumer of the multimedia content?
As long as someone upvotes or tips said content, and they have even a tiny bit of HivePower (HP), then yes. For example, if someone with a lot of HP upvotes you, you earn a lot more money than someone with a brand new account and basically no HP yet.
This in addition to earning HIVE as a creator of my own multimedia content?
Yes, that is also correct.
Should I visit a site such as YouTube or Break.com and the content creator uses Hive-Tube v5.5, I would need to identify myself using my Hive account name in order to earn for any likes I get for comments I leave?
If you run a Hive-Tube server and publish a website that people can upload videos to, then you as the Site Host can earn a % to cover your costs (I would not take more than 5 to 10% max), and the video Creators that post their videos to your server can earn a % as well as long as they have a Hive account username typed into their account settings on your server. If however you are posting their videos and they do not bother to get a Hive username, then the funds cannot flow to them and the Site Host essentially gets 100% of the payouts until that Creator finally types in his Hive account username into his settings on your server. The reason why I recommend that you keep your Site Host payout % below 10% is because what Creator out there will want to post his videos on your server if you take such a large cut of the payouts? That Creator would probably find a different Host to post his videos to that takes a smaller % of the cut of the payouts. Sorry that sounded a bit redundant, but I want to make it as clear as possible.
Oh, and thank you for the Pizza! :)