The template was not suppose to solve your issue it was suppose to show you how to interact with a domino document data source as a learning resource and enable you to figure out what you need to do. If you only want to allow someone to edit part of a document then only show them the fields for that part and the rest will remain the same.

 

for example the discussion allows you to add a document with subject, tags and body. lets say you want this functionality but only to edit the body and not the subject or tags, write your own edit XPage to interact with the data source where you only show a field to edit the body.

 

If I have missed something here with your question and haven't answered it please explain in a lot more detail what you mean by an "Add mod del component" and a sample use case of what you are trying to achieve with it, I have taken this to mean your looking to understand how to add, edit and delete domino documents, which the discussion database will show you very well as it is a fully functional application.