Some time ago I tried to convert a complete Minecraft map that I had made with the
WorldPainter. I had created the world from a pixel-hightmap I had imported to Worldmap. When exporting to Minecraft something went wrong, generating a most interesting map. This I have tried to convert to a Minetest map - which hasn't really resulted in anything playable yet. Nevermind the portico building I used that as a reference point for the WE import.
I never really could decide on what to do with the liquids. I like them in the map but when they spill, at some point they grind the map to a halt. Yet the map is only half the fun if you cannot fall through it. Take note that this is only a small portion of the complete map, wich is exactly the reason I have had problems importing it with WorldEditor. Maybe I should resume this project as the map seems similar to your map request.
[spoiler=some lavaspill]
[/spoiler]
oops didn't notice it was old ...
bumpetybump