Redmine

hi all,

I checked the forum and the FAQ but haven't found anything specific for my challenge. I hope you can help.

Background: Redmine 1.2.1
One project with several users assigned to it.
Besides the manager, there are 3 additional roles.

Objective:
All users/roles can craete tickets.
The users can only assign tickets to users with role 1&2 (but not 3) => reduced list of users
The users can add watchers. The available watchers list is limited to users of the role 1&2 (not 3).
Perfect world would be if I can add additional watchers available in the list for each specific user.

The only idea I have is to create sub-projects and limit the number of users assigned to it.
General it is not my favorite solution thus I want to ask, if someone has a better idea.

Thanks
Christian