Kip,
Well - the CMMC system and rules were conceived/inspired through CM:BO - so the minimum functions are those provided by the CMx1 engine.
Map and unit editors, the setting of individual battle parameters, PBEM support, battle setup by a third party (GMs) and password protection for save game files are probably the most important functions.
I agree - most of those are not very userfriendly and battle setups require some tweaking and/or out of the box thinking in many cases, but as you said, it's doable.
Editing saved games - assuming this can be controlled by setting a special password for editing access - would be very high on my wishlist.
Cut and paste of units from one battlefile to another would be my number one.
In fact, all the functions that were planned for the defunct CMC project would do very nicely. But I guess that was, and is, too much to hope for.