Yes, having some sort of Active/Inactive flag on a layout would be useful; or making it only visible to Master Rights users.
Similarly an Active/Inactive flag on QuoteValet templates would be nice.
Best workaround I've come up with (other than the obvious, work on it in a different system, but that can be a faff) is to create the document as a different document type, so it doesn't appear on a tab the client expects.
However, this falls over if the client has 'all' selected as the tab.
One of my clients suggested something like, have a QuoteWerks\Layouts\UserABC folder - with UserABC being the QW login. Only that user could then see FPC files within that template.
It would be nice if it was possible to create and then work on layouts in a 'Live' installation ie. to be able to hide layouts from view so that the users can't view them until you allow them too.