The feet are 18 mm and the sheet metal is 1.2 mm thick. Since all the enclosure panels are embedded in the frame, there is little point in leaving them out. The cabinet has a corner measurement (height + width) of approx. 32 cm. The best way to see or guess this is to look at a picture of the case (e.g. picture 5 at Digitec).
The front is slightly larger than the corner dimensions (<1mm).