Options for "create and reference"
If you are using the overlay module in Drupal 7. Create the main node but use the Node Reference URL widget on the referencing nodes. This will put links on every node view page that behave similar to the Relationships module. If you add Field Collections module to group all the fields, you can get edit in place with overlay popups on the node.

The workflow would be like this. 1. Create a node. 2. The node form only asks for the title of the node. 3. Return to the node with several different parts, each getting their own popup form or if JavaScript is enabled a return destination back to the node after creating or editing.