Can I Mix Permission Types in My System?
Yes, and in fact its the smart thing to do. Here are some examples, where we'll assume that we are protecting a content management system:
Tiers and Groups
Use groups to decide what content section in your system a user can access in the first place. Then their user tier decides what that user can do once they get onto the page, or whether they can see the page at all.
Roles and Groups
Use groups to decide what content section in your system a user can access in the first place. Then set up roles to decide what that user can do once they get there. Further refine your ability to control access by setting up a role permission that either allows or denies access to each template in your system. Then additional roles decide what can be done if such access is granted. This allows you to tailor, on an individual and completely granular basis, what an individual user is allowed to do everywhere within your system.
Mixing all three types (Tiers, Roles, Groups) is possible but not likely to be the best solution to your problem, since roles are essentially a more flexible version of tiers. However AMPro can handle this without difficulty so the choice on whether to do this is yours.