Videos gone from Shared Photo Stream

YES IT WILL DON'T DO IT

I made the mistake of creating a shared photo stream and deleting the original videos from my camera roll, and now those videos are permanently gone.

That's not correct. I don't know what you did, but videos (and photos) added to a shared photo stream will remain even if you delete them from the camera roll. I just tested it again myself to confirm this. Perhaps you deleted them from the camera roll before they were uploaded to the shared stream.

However, since at the present time you cannot download videos from a shared stream (you can only play them) it still isn't a good idea to delete the originals as you will not be able to download them again from the shared stream.