When I work, I always imagine bits of sequences that can be moveable in order to create a scene. If you ever used a music sequencer, you might understand: you have a general pannel which contains the events on different tracks and they can be played simultaneously to create melodies.
You are right Pytom when you use your code to display a character and make it talk. The scene shows up and everythings fine.
You are also right when you mention movie scripts. They are indeed written on a textual format, but they only show what is being played or to be played : there are no parallel paths.
VNs are a little different from movies because you have to take on account that there are multiple paths, parallel events that happen at the same time on a timeline (sometimes in VNs, there are loops which make that kind of timeline more apparent, like in higurashi no naku koro ni, cross channel, school days...).
I don't intend to say that Ren'Py way to process scripts is flawed. It's really good and my opinion on this isn't going to change.
I just wanted to highlight the fact that it is much easier to manipulate a representation of an abstraction (that is to say a representation of a scene for exemple) than a block of text which contains multiple ideas (or multiple abstract ideas).
Imagine a bubble you handle to be shown at a precise time and another bubble which might be shown according to a player's choice.
That's why I thought a storyboard is much easier to handle than a text representation.
I experimented with Labyrinth, that I found in the ressources thread. It helps when you have mixed situations, multiple characters, multiple relationships. It made me remind of those tools FBI and french police use to retrieve someone through their similar acquaintences.
Erm, well, back to the topic.
Somehow, I disagree with mikey on this issue. There are people who are storytellers but not programmers. Some people don't even catch on concepts like methods and functions. There might exist a barrier that repells those who want to tell a story. After all, Ren'Py was made to allow people to create stories through games (originally a story about Onegai Twins if I remember well hehe), not to create an elite of programmers (at least I hope so).
So when Pytom tries to simplify the coding issue, I prepare kudos
Gambare Pytom~