Crowd has a concept of Roles. They are basic, more or less just a list, but they are there. JIRA ignores them.

When crowd integration is used, JIRA should get its list of roles from Crowd. It should still assign purpose and such things (permissions based on these roles, group/user memberships of the roles (both default and per-project)) in its own data store. Just like it stores user's profile information in its own database. However at least I should be able to add/remove roles from crowd.

In future (though this is a crowd issue) it would be nice to be able to manage the default (non-project specific) group/user memberships from crowd. Right now I can add a user to a role, but not a group. But that is, as I said, a crowd issue.