Well it looks like it may have just been some miscommunication and maybe some over-interpretation of various statements, but it does appear that scripting within the editor will hold when played in the GM mode. I never expected scripting within the GM mode itself (though as explained above, a scripter should give simple tools for the GM to alter scripts), but that seems to be what the discussion was about. Here's Michael's response:
I guess the miscommunication took place because we were talking about Gamemaster Mode and what is possible inside the GM tool itself - which simply doesn´t support scripting in any way like stated. Hence my explanation how you could solve things with this tool, the way it is intended.
The modding tool on the other hand is something completely different, which does not necessarily has anything to do with GMM. As a further complication, I haven´t looked much into the modding tool so far and was not aware of the final extent of things you can change until this stage.
So in this hindsight, you are right and the answer to your original question [about whether in-level transitions can be added] is "Yes", if you are going to use the modding tool to alter your campaign. My apologizes for the confusion!
He also said character/item scripts should work fine, so that's a major relief as well. It would be nice to hear one more clarification, but I'm pretty satisfied that scripting within the editor will work in the GM mode now.
