Anna, first off, like everyone says - you are a stunner! They've got to pick you for that!
I LOVE Big Brother!! I watch it every year from beginning to end, and I do agree that you need to say something "out there" to really get their attention - but what though?? I think the people who tend to get on are the ones they think will make great viewing, ie by saying that you are really intolerant of airheads is just the ticket!
I do love the video, the first one especially, but again it's very normal and you come across as lovely, but I do think you need a USP I think they call it in business (unique selling point!). WE HAVE GOT TO GET YOU IN!!! I'd love it so much! (Even if I think you are insane for wanting to do it!)