Something I'd like to see in the web app -- a quick way to edit the labels for all my content at once. Here's my idea for what to do:
In the right-top menu add an entry for "Labels". This takes you to a page that lets you choose from a list of labels (with a way to create a new one). Choosing a labels shows you posters for all your content, and you can simply highlight/unhighlight a show by clicking on it to affect which shows have that label.
As a bonus, have a button for "All Labels" which shows you a list of all your content in rows and all known labels as buttons in columns. Extra credit for allowing the user to drag the columns into a custom order.
