BSP Brush in BP/Selection of Vertex

First of all, what exactly is the difference between a BSP Brush and a Static Mesh? Of course I know that I can edit a Static Mesh outside of UE in programs like Maya oder 3DS Max but is there another reason I should use/create Static Meshes?

And that leads me to my second question. Is it possible to create a BSP Brush in a BP-Class? In the Level BP there is no problem.

My last question is now, if there is a possibility to select and translate a particular vertex of a BSP Brush and/or a Static Mesh in BP. (dynamic transformation) Also it would be nice to select the Material of particular face.