Roles by Project

it would be great if we could specify roles by project in addition to roles by person. Use case:

We have two folks who are project managers and one "I like to play" executive-type. They need to have visibility on all projects. However, because of their role, they have complete freedom to make any changes to any project - even ones they are not managing themselves.

Similarly, one of the project managers may have a role in someone else's project where she is NOT the project manager. But to give her any role at all in that second project, she is given complete project manager privs.

IIt would be great if the "role by person" wound up being the DEFAULT role a person had for a new project, but they could be reassigned to a different role for that project in the screen that assigns them to the specific project.