[Endoperez]

The only thing keeping users from creating awesome scenarios is, IMO, being unable to add custom messages for:
1) starting the game
2) winning the scenario
3) losing the scenario

In addition, it would be nice if messages could be "triggered" with some other events, such as:
4) defeating a certain enemy
5) conquering a certain province (the first time)
6) having a certain amount of victory points/dominion/research/etc (the first time)
7)losing a certain province (the first time)
8) losing your god, prophet, or a spesific unit (probably checked with unit ID number)
9) perhaps getting back the unit of point 8 could also give a spesific message.

The first three would be enough for scenarios. The others would allow the making of full-fletched, semi-random stories.