the 1200 dust covers are wire mesh, and water is fine to use, that is what i use.
so lets say if its sitting on a desk, dust isnt a big issue?
never tried no dust filters lol
your rear fan wires will fight behind the mobo tray
you can see the wires going behind the panel in the top of the pics.
all my case fans in the rear and top go to one molex and all the front fans go to another molex, on the same rail.