Noticed your comment about the 50/4 making noise while shaking-- Mine does not. There's probably some variation between the two, and maybe some issues if it's making noise, but I definitely have great sharpness corner to corner @f/8 after checking prints under magnification. The others sound pretty typical to me in their behavior, after testing out pretty much a whole case of enlarger lenses. 2 stops down from wide open is a good starting place for most good, but not necessarily new, EL lenses. Having to stop why down on a Componar is typical, and 1-2 stops on a Rodagon seems pretty reasonable.

EDIT: The 5.6 Rodagon 80 is an older one in the Rodagon series-- quite nice lens, but stopping down 2 stops is definitely par for the course (for older nice lenses) to get good corners. Just like older Componons-- definitely wouldn't expect to be able to use them wide open.