SetSyncRate and SetVSync are mutually exclusive, they will overwrite the settings of the other. The following applies to 108 and beyond.
Using SetSyncRate with a value of a value other than 60 will turn VSync off and use your chosen value, using a value of 60 will turn VSync on as it should be a smoother method of achieving 60 fps.
Using SetVSync with a value of 1 will let the system handle the frame rate (usually 60fps) and set a manual sync rate of 70 as a backup, just in case the system does not support VSync.
Quote: "2) media encyption?"
Media encryption would be a nice feature, not in the near future but at some point.
Quote: "3) improve drawing speed on android from 1076?"
I can't think of anything specific that would have improved pure 2D drawing since 1076, only that it decreased performance in early 108 betas and has since returned to 1076 levels.
Quote: "4) Any enhancements in the music and sound areas?"
Nothing planned