[Zope] users, properties and roles

[John Hunter]

I am writing a zope2 workflow product.  There are a variety of roles
in the flow: a researcher, administrator, reviewer.  I am in the very
early stages of implementing the product and am wondering how to best
reuse zope's users and rolls.

For example, I would like to have extra properties on my users, say an
email address, contact phone etc.  Is it good practice to subclass
AccessControl.User.BasicUser and BasicUserFolder to add properties to
the user?

Is it good practice to add the additional roles (researcher, reviewer)
within the standard manage_access framework?  In out project, these
roles can overlap (you can be a researcher and a reviewer on different
projects in the same workflow) and do determine access level
information.

I've looked over the  User Management products at zope.org.  Does one
or more of these come recommended to support, for example, easy
addition of user properties as described above?

Thanks for any and all advice!
John Hunter

Zope-2.7