You don't need to watch it on youtube. You can use CTRL+SHIFT+S combination in tech room to get acces to all movies. Same goes with database and mission simulator.

Silent Threat: Reborn is the best user made campaign I've ever played.
Even though it's finished, its creators still work on particular assets as mainhalls and one very important ship :D.

Yes, Silent Threat Reborn is a very solid campaign, far better than the original Silent Threat IMO.
Have you tried BluePlanet : War in Heaven part 1 ? It's still a bit rough around the edges, but I find it amazing. The new UEF faction with its unique military doctrine makes for a very refreshing gameplay. I can't wait for the release of part 2.

Yes, I've played it several times, but as non native english speaker I prefer campaigns with voice acting (otherwise I have to stop mission every few minutes and read the dialogues - action is too intense in WiH to do that while playing).While Blue Planet planet is fabulous spin off, it also lacks that special Freespace feeling. It doesn't mean it's bad - it's just different. That's why I prefer ST:R, and cannot wait for super enhanced and extra polished rerelease of that campaign.