iTunes App Store, GPL is incompatible so it was pulled by request, I've still got a copy on my iPad though.

I've downloaded VLC and XBMC when they were both available in the App Store, hod do I re-download? They dont appear in the "purchased" section

Ir they don't show I'm the purchased section they might be gone forever, I kept a backup of the IPA file.

Don't think so, considering the limitations as to how many devices you may download the application to. If i am not mistaken was it five.

There is no limit.

This limitation is gone.