I'm not a "pro" of ux but at Synectique I make the css of our web tools.
So I can try to make some mockup of widgets when I will have some time

but I will not have the time to implements them in Pharo/Morph.

Tomorrow I will send a screen of the nested list we made at Synectique.
It's a responsive tree with icons at the right and/or left.

And also I know the priority is the features. I just make some notes of
the main UI problems because it's something that should not be forgotten
after the features implementation :) And I am well aware that it's hard
to find time to fix design. (Tests, doc, design, promo, bug correction,
speed up��� Too much things to do after making a feature :D)