Re: DVD angles
It's a shame no-one uses this really, I always thought it would be great for something like a "trapped in a mansion, horror/zombie film, where you could choose to watch different bits of it all happening at the same time, with different stuff happening in them. Ie if you weren't watching the arguing teens, you could see something coming in an "empty" part of the mansion. It would mean that you'd have to watch it several times in different ways to get the whole experience.
The main problem with a lot of interactive stories though, is that that they are ultimately limited by how chaotic they become, very quickly. Either your choices are essentially meaningless and only make minor alterations along the way, or you make multiple choices all the way through and end up with only 1 or 2 set endings to choose between. The challenge of scripting and making something that isn't like this is insane, even games don't really do it. This is why in tabletop RPG you have a human controller who is able to improvise and react to what choices you make. Having to pre-plan so much is an impossible task
Biting the hand that feeds IT
