Hi, Thanks!
I think the pictures in the link answer most of your questions
1.) yes
2.)You can build up the base as you wish. It is a bunch of 3 in square yellow"cells" that interlock as needed.
3.) There are two variations of wire cover systems. A single simple cover, and a double layer one with a quick-disconnect retainer
4.) The proper nuts and bolts associated with each. Nuts have a retainer.