Hi Robert, sorry no there is no visual editor it's all just edit in a text editor and test it with MoI.

It is helpful to set DisableFileCaching=y inside of moi.ini to make MoI reload files on every run rather than caching them in memory like it will do by default, see here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6727.2

- Michael