having a scripting language may be interesting but I'm not sure if it is worth the work to add it.
Your example seems pretty bad to me as defining a map such as you did will only create awfull maps. From what I've seen, widelands (another open source game) more or less uses it and I think that their editor most likely handle it but that's not our case.
IMHO, the most common use for such things will be the campaign. That would allow to define custom events (creature spawn when something happens, ...), camera behaviours (moving the camera somewhere when a certain tile is dug, ...), displaying some popup explaining something in the story at some point...
To do such things we only have 2 ways:
- Using a scripting language such as AS, LUA or python (From what I've seen, most open source games seem to use LUA - at least UFO AI and widelands so I would go for it).
- Hardcode some commands in the level file just like we did for the other things (goals, seats, ...)