Moving Issues Across Projects: Private Fields

Hi,

We are evaluating YouTrack and looking for a solution to have three separate groups (BA, DEV, QA) have views into a project, each with their own private fields.  As I understand it, there is currently no functionality for sub-projects.  So I am playing with 3 different projects then creating workflows that can transition issues from one project (group) to the next.  For example, when a BA moves an item from 'Analysis' to 'Assigned', the workflow will move the issue from the BA project to the DEV project.  BA users have reporter access to the DEV project, so once it is moved it is up to DEV to move it out of theirs.  This part I have already sorted out using workflows.  The outstanding items that I cannot sort out in YouTrack if they are possible or not:

1. Lock changing the project field so users cannot change the project manually but will rely on State transition to move across projects

2. Private fields for each project.  I can create these but they seem to get wiped out when moving across projects.  Is there a way to maintain the private fields even though they may not belong to a particular project but are viewing by another group?  For example the BA project has a private string field called 'BA PRIVATE'.  When I add a value to this field and move it to DEV it disappears.  And if I move it back to BA the value is empty again.  I'm looking for the ability to have private fields for users across projects.  We are open to any creative solutions.

Thanks

-CL.