Xaart, hello! Thank you too for reviving the topic. I will continue to post my reports; expect more soon.
You should have written about your map editor problems a long time ago, as it is often absolutely necessary! Without reinstalling the game, you can solve your problem with the standalone map editor. Just unpack the archive into a separate folder and use it.
Also, the ProspectorRT utility is very helpful when you have difficulties with single-player maps. It analyzes the starting save and displays all the information in the form of tables.
The map "Dreamland" (by the same author, Jimmy, who created "Seven Seals") was already uploaded to maps4heroes.com, and now it has been re-uploaded. I downloaded and checked it: the map's date in the archive is 08.11.2007, so it is not a new version, but the same one. I haven't played it yet, but I will definitely try it.
I am also interested in this: please indicate how many months it took you to complete a particular map – it is useful to know in advance what to expect, because not everyone has the patience for a long map.