Lock Workbench content until moderation state change
There is a really cool module called Rules Forms that could help here.
https://drupal.org/project/rules_forms


You have to set it up so that it works with your particular content type. See admin/config/workflow/rules/forms
Create a Rule and set two Events "XX node form is being built", and "XX node form is being validated", where XX is your content type
Set an Action called "Set an error on the form" and then choose "Title" for lack of something else, and then enter a message about this node being locked.
Set up the conditions as needed - probably need to check the user id and the state of that node - this is the part where I can't help without seeing your particular site.


If you don't set any conditions, nobody will be able to create or edit nodes of this type until you do.