Disable creation of a page for a content type and just use teasers?
As far as I'm aware, every Drupal node created has a "page" created for it, no matter what. You can disable the creation of a user-friendly URL, but all nodes have a node ID, and since the node/id URL path is in reality just a simple query, all nodes can have "pages" generated for them by querying against their node IDs in this way. 

I would say as long as you just refrain from placing these content types into a menu, you won't need to worry about it. It's highly unlikely that a user would manipulate a URL on their own in order to find the content's page.