Drupal Civicrm searchable profiles
A couple of ideas within your framework: 1) Use civicrm fields exposed to drupal user registration and do away with the fields from the drupal db, so everything is housed in civicrm.

2) Write a Rules action to update civicrm fields based on the drupal fields so you can display them.

Our solution to the issue of displaying civicrm fields and drupal profile fields uses views 3 integration for a 'civicrm membership view' and better exposed filters to search, which is a different strategy than the link you provided and from what you have built out so far but it does the job well.