The data would still be accessible via saved searches and the like if scripted right? You cannot control that type of access on standard fields?

you are correct...every workaround I see for this still allows searches...most of the time I see workflows to trigger an error when restricted customer is brought up but it never stops the search

@Mike what @C_Billings_ said. Let me know if you do find a workable solution. I'd be very interested in being able restrict access to certain projects.

Yes, and even customer records.