Hi Joris,
Thanks for sharing the above - very helpful!
Here's what I decided to do:
Since each business area has their own form for say Contact with their own specific preference options e.g. events, newsletter, professional network 1, 2, etc.. I have created a "Business Area 1 Comms - Do Not Allow" which then takes people out of all Dynamic marketing lists so they don't get emails. The field is available for edit only during "Create" state of a form so users can set the initial option and then gets locked and managed purely by the individuals preference.
Also I have created a Subscription List which is called "Business Area 1 Generic" and called it "Unsubscribe from all the above Business 1 topics" on the preferences form so once subscription preference is submitted I get my workflow to update the Business Area 1 Comms field to Do Not Allow, and set all preferences to Out. I also put a rule whereby if all Business Area Comms - do not allow fields are set to "do not allow" at any point that sets the main Bulk Email field to do not allow.
I had to keep the generic field "do not allow bulk emails" as we've got an option whereby 1 user can restrict ANY communications to a Contact globally (e.g. CEO of a company or sth..) so once somebody is set as "do not contact whatsoever "there - all options get put into do not allow and locked unless the owner changes the option...
Hope this works and good luck indeed! :=)
Adriana