Hi Guilherme,
I'm glad you liked it.

> Still wasting a bit of space on the top, somehow the 1st Tool - Draw curve - leaves some empty space whatever is the UI size. Strange.

I think top space is like BurrMan said, reserved for tool settings and object properties. At least all tabs are ungrouped and visible now :)

> Like a lot of your UI style, quite elegant. Care to share?

Of course. I'm sharing my complete ui folder as zip because replacing moi.css is not enough for sharp viewport corners. There are some edited png files (it's been a while, I forgot which they are). I edited them because I believe that's the only way to get rid of those ugly blue tinted, rounded viewport corners :p