I am not an Apex expert but I am guessing that just like you added

<chatter:feed entityId="{!Id}"/>

to show the chatter feed, there should be calls to pull the field I want to update, right?

Do you have any documentation I can check on this subject?

This is my use case: The sales team start managing their opptys directly on a dashboard, they update amounts/stages/dates from there without having to open X amount of records. In about 1hr after the team completes the management task, their managers have a meeting and they have all the updates ready after the sync and dataflows run. The managers will use the same exact dashboard.

I don't want to start creating tons of individual actions. It would be 3 or 4.