Edit Contact Roles in the Potentials Mod

Edit Contact Roles in the Potentials Mod

New to ZOHO so I need some help. 

I work the same people on different projects concurrency. Their contact info remains the same but their role changes from project to project. 

In the Potential Mod you can pick contacts and assign a Role to them.  I know how to edit the roles. What I want to do is add some fields. Specifically I want to add the following "Expectation" "Requirements" and "Communication "Requirements." This will allow me to look at a Potential and see information associated with this contact but only for this Potential.

For example Bob is a contact- on the Acme job he is the client and wants to be contacted at the end of every day we work on his project.  On the Capital Bank job, Bob is the General Contractor- he only wants a weekly work summary delivered by noon on Monday. On the Evermore project, Bob is a subcontractor and needs to be notified when we are three days out from completing our work.
Any one have an idea how to make this happen. ZOHO txt help said that you can't add fields to "client role" anyone know how to associate a contact with a Potential and add info that will only show up when the contact is viewed in that potential?