You could put those attributes on a subpage with a display condition.
First yous create a new subpage and then create the condition, create section(s) and put the attributes there.
In your case you would have to have several to match all the options that can occur.
Below are two screenshots how you would get started with that by creating a new subpage in project edit properties
As far the collaboration documents are concerned there is a job for purging documents
Purge Documents Purge documents according to the specified parameters, but I think that applies to documents not deleted by the users. It may be that once a user deletes a document it it gone permanently.
You can confirm it one way or the other by doing a test and looking at the clb_dms_ tables like CLB_DMS_FILES.
I have tested attachments. When they ale deleted by a user the are gone for ever, unless there is a database backup.