That is not what I am saying.
One caveat, I haven't used calendar or acs-events since I left AD in 2000. The calendar module was a mess, but acs-events and the other packages were working as expected until the java bug hit.
acs-events has all the logic to store events (at least it should have).
Private and public calendars were all part of the spec. I am mainly saying that any event related data should probably go into acs-events, or if that doesn't work (can't see why it wouldn't), extend acs-events.
That said, I could see a few ancillary tables with non-date data if needed. The whole point was to have events stored in a common data store. That is just good data modeling anyway.