You can import movies, in AVI or MPG format - just import them through the standard way (Resource Manager) and go from there. And of course, use an event to Play Movie (the command's on page 3 of the event commands list)

A score system would simply have a dialog box at the end asking whether or not you want a "New Game+" or something. If you do, you'll have to have a BIG event to reset every variable to 0 (except your scores), every switch to OFF, and all heros to level 1 and all items to 0 (unless you want to keep everything, you should still remove key items though). You'd also have to set up your party so you start with who you're supposed to start with. After that, just Teleport to the correct starting location and let the game play again.. using your "new game + score" events.