What approach for showing custom user fields on a node?
Ok, I'm only using drupal 6 but I think these answers can lead you to a solution:


With the core profile module there is a block "Author information"
You can use the Author Pane module but it doesn't have a stable release for D7 yet.
You can use views to build an author block:


If you're using profile from core:


  Create a user view
  Set the argument to User: uid
  Choose "Provides default argument" set to "User ID from URL" and check "Also look for a node and use the node author"
  Add your user profile fields.


If you use Content Profile


  Create a node view
  Set the argument to Node: Nid
  Choose "Provides default argument" set to "Node ID from URL"
  Create a relationships to retrieve the content profile
  Add your content profile fields.