AGEod team has always made clear that they were very open to third party scenarii and to mods. However, Pocus has chosen to give priority to the engine and AI code for now rather than developping a real user friendly editor.
For now, Pocus said somewhere on the forum that he was planning to release the instructions for scenarii editing along with patch 1.05. Rabid fans can already begin to work on their OOB, events and victory conditions... (thus I will be able to play them soon!!!
NB: If some scenarii look really bogus to you, you can already give your suggestions to Philippe Thibaut, or preferably discuss them in the Map Forum, where numerous American revolution fans will be pleased to join.