petitminion fair questions!
Yes, by "push" I mean upload. By bucket I mean the datastore or whatever: the place where content will be kept. Those two things are necessary to solve the limitations of libraries. See uploading and organizing user stories as described in epic1 for more details.
Organizing the library into collections of (somehow related) albums and playlists is essentially one half of what libraries are used for. Mockup in #1448 illustrates how it could be done in a much more straightforward way than what we currently have with libraries.
By group I meant collections, as above. Ie I was speaking of following remote libraries replacement so that they would appear in your own library, alongside the content you uploaded yourself.
I Hope this is clearer : )