Metadata on the PR4100

I’m currently using Plex on my PR4100 and while pondering expansion options, a few questions came up:

  1. Is the metadata always stored in a single location or is it stored on the drive (or array) where the media is located?
  2. Is there an easy way to find out how much metadata has been downloaded in total?
  3. Would I be correct in assuming that if I delete media, the associated metadata is automatically deleted as well?