Your question is becoming too complicated for me, as I'm not a developer.
But, well, I guess you could, as you suggest, create an
action plugin that catches the
IO_WIKIPAGE_WRITE event. You must get the event
BEFORE the page is actually saved, otherwise, it will be almost impossible to distinguish between page creation, edit and suppression. In the event handler, you could modify the data plugin database, add and remove components in a field alias. Possibly invalidate DW cache. This should not be too difficult.
Now, modifying another plugin database is probably not the best thing to do. Is there another solution ? I just don't know. Although a bit hackish, this should work.
The "See also" section on page IO_WIKIPAGE_WRITE, will lead you to PHP code of all the plugins that use this event (including the data plugin itself).