Yes on all of them:

1. You have to do it in med. select the faces, and apply the skin that has the appropriate shader linked to it

2. Chris answered

3. Could be done a couple ways. make a quad the size you need of the screen and keep it lined up with the camera. You could also do screenspace testing in the shader to determine what portion of the screen you are.

4. Yes they can be passed. A quick read into the manual looking at material skill etc. will give you the info you need.