How about using a "Ribbon" Like MS Office?

My chess software, Fritz, used to have a clunky and esoteric GUI. I used to have to hunt down features in sub menus and dialog boges much like BIAB.

A couple of versions ago (ver. 12, they are now on ver. 14... another program I need to update), they decided to adopt the "Ribbon" interface ans things are much more intuitive.

I think BIAB would benefit greatly from this.