Is there a script that simulates facebook's video post? where you can paste the link in your post, and it will automatically bring up a preview and description of the video? Or is this simple enough to do without a script? How would I go about this?
When you paste the link you will need to parse the link to retrieve the video ID. Once you have the ID you can get the video information from the Facebook Graph.
This should give you an example of the data available: https://developers.facebook.com/tools/explorer/?method=GET&path=me%3Ffields%3Dvideos