Pat, Having worked on the CDTV ROM I can tell you that the ROM is 1.3.
Workbench 2.0 requires Kickstart 2.0 which is not in the ROM. Not having
any official affiliation with CBM at this time I can only speculate that
perhaps a future CDTV may support 2.0 but the currently shipping hardware
does not. As far as the joystick port I've got no current info.