Well even if there are a few problems, most can be fixed behind the sences without changing any of the parts of the API. Worst case we will need to add things, but that won't break clients.
When submitting content what is Media ID for? Also the thumbnail is a bit strage
Files must be less than 32 MB.
Allowed file types: png gif jpg jpeg.
Images must be smaller than 160x120 pixels.
Maybe support either uploading to the site, or just providing a url.
I've uploaded the update, obviously what you work on is up to you, but my suggestion would be
1. add the missing parts to the Create Media Resource page (live stream, extra languages?) to help with getting content added
2. Work out how to do /api/regions and /api/languages so that I can fetch a list of available regions and languages
3. Add the remaining fields to the response
4. Templates