[note: The PDF multimedia file only runs with latest Adobe ReaderX version which can be downloaded 4free at Adobe website]
Regarding mobile devices:
NO pdf till this moment can run audio/video. It is a 1million prize :)
although I can package your PDF to be a native app that can run all multimedia that you desire especially on Android (ios limitations)
1- The video plays within PDF itself
2- Provide youtube link or links to your videos and where to insert
them in your P D F.
3- Modifying your P D F requires more work on my side and will ask
for more gigs.