(Whats subscribing about anyway?)
As far as I'm aware, (I don't really use YouTube on a regular basis) anyone who subscribes to your account, will recieve notifications every time you post a new movie.
So, they know when you've got new stuff instantly.
It's pretty interesting, but personally, I would've thought it would look a bit better if you did something like;
Built the Exterior Tardis on a large outside scene, then, build the inside underneath. Using SetPlayerTransform events, you can teleport yourself to the inside (underground), once the door is opened, so it's like the real thing is bigger on the inside.
I like it though. The Main Control room, if designed to the current series' Tardis, should be a bit bigger. As should the Library. It was many, many times bigger in the Doctor Who Movie. And the entire room was filled with wooden bookshelves, large ones with Ladder railings, and wooden tables and chairs.
Very nice though, well done.