How to enable users to add content only from some pages (and only once) in  Drupal 7 i currently need to implement this use case in drupal.

We have two different type of users: registered users and moderators.

I need to do the following:


registered users can add only one
particular content type: videoCV (no
help needed on this subject)
registered users can add this content
only from a pre-definite page called
"Create you Video CV" (the page is
accessible in the main menu) and only
once
moderators can add contents wherever
they want.


so i need on these points:


how to limit to registered users the
possibility to add content only on
one page?I mean have the link add
new content only on that page? (and
also change that link so that it
reads add your videoCV
how to limit users so that they can
add just one content?


any help is appreciated, i think i can solve point number 1 withouth particular coding, but i think i need to create a custom module for point number 2, that is no problem!
Content Profile module usually bounds the users to create exactly one node of some content type that has been marked as Content Profile.

May this help you in this regard.