Workflow approach for anonymous users, or limited roles to create events
I admire the principle of not being too ambitious in building customizations, but I worry that you'd be going through far more trouble than you'd need to.  You might consider just building a custom Drupal module that did exactly what you need.

Set up a Drupal form with all the fields that you need.  Then in the submit function, use the CiviCRM API to create the event, location, and whatever else--including leaving the event inactive.  It won't be very reuseable, but it will be more reliable and understandable than a Rube Goldberg Does Drupal sort of contraption.