While the engine is definitely still limited, I think now is as good of a time as ever to start mapping for FH2.
One of the FH2 developers (TS4ever) has released a video series on making a map for FH2 that I recommend viewing. He probably answers a lot of the questions you have/will have in the series.
https://www.youtube.com/watch?v=WlOMa5hjrOk&t=3250s (Part 1)
Once you get the game working, I recommend getting the editor working, all the files that are necessary get extracted, and also, I'd install bfmeshview. This is a very handy tool for viewing/editing static models.
http://www.bytehazard.com/bfstuff/bfmeshview/ (Version 2.5.3)
For setting up the editor and extracting files, refer to the following link.
http://forgottenhope.warumdarum.de/tutorials/index.phpAnyways, good luck and above all have fun!