Hi, I'ms also quite new with superpowers and haven't had the time to fully explore all the features it has to offers, but I totally agree what have been said by you guys.
Also I find GrandSchtroumpf's idea about getting a easier way to customize the UI by creating easily new theme more interesting than just adding statics new ones.
Finally, and I talk as a graphic designer, I think that this engine have to use his "outside the box" look as far as possible, compared to others (enven non web) engine it's a big plus. If the possibility to easily customize the editor & UI (like in Zbrush) is added (while keeping his user-friendly design), it will be far more friendly for those who are more into graphic creation than development.
I don't know if my advice is very usefull because far less precise than the other but I will post others feedbacks as soon as I have new ones !