Finally gave in after being driven up the wall by MonoDevelop for the last time... Moved to Microsoft VisualStudio on Windows, ah now everything just works-ish
Took forever to get communication working between VisualStudio on Windows and Unity on the Mac, so that you can double click debug logs entries and files in Unity and have it jump to the right Project / File and Line Number in Visual Studio running in a Virtual machine on the Mac. Had to write my own PC EXE acting as a bridge and all kinds of funky stuff... But I just couldn't stand MonoDevelop or Xamarin anymore, they are such junk.
And I'm really fretting and struggling around the concept / design / look and feel. I need to nail it down now, but it is impossible to draw or even photoshop mockup any of the themes I have in my head.
Maybe better approach is to have a few visual ideas / concepts and start playing around in Unity bringing them to life, then in a serendipitous manner discover and stumble upon something I like that I may never have thought of otherwise. Just get the wheels moving instead of being stuck in planning limbo.