A custom form and display a comparison table

Drupal 7 custom module 1. A form on which users can select the existing nodes (for quiz module) and users. I am using node reference and user reference to select the node but I have requirement to group the nodes together with a taxonomy field which is not possible out of the box. One level workflow for approval as well with workflow module. So form_alter needs to be done. 2. Create a custom display page(views) where we can display above selected entries for each node as line item and display a comparison table using db_query. It should include columns of above (which is what quizzes, users must take), what is the latest version of that quiz(field is available in the node) and what they have already taken and highlight if latest version of quiz is not matching the version the are supposed to take. Al these data is available in the database. The report needs to have contextual filters to present the information to various roles. Eg: if the person's department is 'xxx', xxx's department's Head must be able to see all the users under him with the above data. We can think about having multiple view displays using views module regarding the display.