I'm not sure which method you're using to embed the flash - you mentioned that you uploaded to root the video and JS so I'm assuming you have source code access. From my experience with the platform, it doesn't really behave like you'd expect from an ordinary server.
contact ning's support re your cross browser computability issue - they're really good.
I was playing with language options for members but not with Google translator so I hardly help you with your issue. Try to check translated.ning.com There was a lot of info on translation options for Ning networks.