1) "Have crime rates risen or fallen since the expiration of the Assault Weapons Ban of 1994?"
Can't do this one until much more time has passd.
2) "Where the provisions of the Assault Weapons Ban of 1994 justified, or were they a result of media sensationalism?"
This is excellent. You can add to this the media hysteria as the bas was about to expire. Concentrate on the wild claims made, and the reality of the AWB. For example, "Machine guns on the streets" (no, that was taken care of by '34 NFA), "AW's the preferred guns of criminals" (no, handguns in the same models and calibers preferred by police), etc.
3) "Do crime rates increase or decrease as gun ownership increase?"
"More Guns, Less Crime" by John Lott. And many other studies have shown an inverse relationship.