Yes Eric php has reserved functions for things like count etc and a deletion of a page is rough but would be one option. Never "Killed" a file yet but why not. I think I pointed you at that flat file system Eric. A database system can be uploaded running without the necessity to open a MySQL database. The conditions can be hard coded for interaction. Could handle most requirements not Google's.
Basically the script will count the records and when it reaches the magic number either deletes the record and redirects to a sorry page or pulls the plug on the form. There are probably more elegant solutions. We will see when we go out to play.
I am hell bent on this A La Carte responsive program but I can see a back end for forms is a possibility to get my hands dirty on.