"3) To make mesh cleaner, more beautiful (from Sketchup. Yes, beautiful mesh is more valuable :)"

you keep saying this.. and as a Sketchup Modeler, I can produce "beautiful" mesh easily.. it's not the program at fault but the operator. any modeling app can produce crap mesh if you don't use it right. I model in Quads, I get Quads. that simple. so how about you drop the crap and get on with the subject?