Depends on the format they're in. If they're in GBAMP format (.gbm for movies and .gbs for audio) then it may be possible, by using the "filmplay.bin" file on the SC website. If they're in M3-specific format, then probably not.
the "This occurs after you have posted 5 messages on the forums. Your account will be automatically upgraded to 'Newcomer' within the hour, unlocking additional features such as posting links and more." message wont go away