Let's see if I got it...
Collection - Basically, I can "subscribe" to people, but not albums. I would place an album in my collection and be able to see when someone edits it.
A collection is basically something that is for me, not for the site (but can be made public if I choose). I can add a collection to my account and I am not going to get a bunch of "no votes" because one thing isn't related to the next.
I guess, maybe, if you could give a brief explanation between a collection and a subscription, that may help as well.
Tags - Never saw that page. But, my confusion is, why can I hide them? And, other then the fact that everything is editable, why would people be able to delete them?
And, of course, since it is search-able, it should be "verifiable"? Like, I should not tag Pavarotti with Punk Rock or Porn Star.
Ratings - User opinions. Not a legal/verifiable rating such as Metacritic. My opinion, not a list/accumulation of sourced content.
And I forgot one.
What is ANNOTATION?
I understand what/why we use Disambiguation. But what is the difference with that and Annotation?