Thats a very nice idea, but difficult to handle if many requests come..
The new features sound great (excluding the last "feature" - the new one will not be free )

You could add a little program creating a file with an simplified algorithm, or with variables needed for a dll intern algorithm. This file is different for every user, because he/she has to create it on his/her own. When the game with the dll is published, this file has to be included.
This way, you only have to sell one program 'package', and not individual ones.