This looks wrong to me, at least the Ring 2 stuff. I thought it was the DOS (and Win) VDM's that run in ring 2, not the graphics and print system. Ring 2 allows DOS device drivers to be generally used.
As for CPI, if it means what I think it means, everything depends on it. A full screen session only needs it, some device drivers and their corresponding DLL's, eg mouse.dll. A minimal OS/2 system boots to a full screen session without any graphics driver, think booting off a floppy.