I think the proper way to do this is to add permissions on the fields and workflow on checklist, which will be fairly large changes. For example:
Fields 1, 2, 3 ... 9 are fulfilled by the member. Member submits application form. Application form is held in 'pending'
Moderator is notified of application form. Moderator fulfills Field 10, which is only available for Moderators to view / edit.
Application form is finally posted to topic.