As pointed out in my question regarding Employee Community vs. Chatter Plus the major difference between Chatter Plus and Employee Community is that Chatter Users can access salesforce via login.salesforce.com while Employee Community users have to use a community (portal) login.
After the implementation of a customer community, Salesforce allows you to decide whether or not a chatter post is shared with "all users" or "[your company name] only". (see figure 1)
A customer community, a partner and a employee community are in place. An internal user wants to share a post with all employees (employee community and standard salesforce users).
Is it possible, as a employee community user, to share a post with internal user but not with customer and partner community users?
Is it possible, as a standard salesforce user, to share posts with all employees?
It the chatter feed of a Chatter Plus User the same as the feed of an employee community user?