if I understand this correctly, you wish to use the submit button to commit data to db from the VF page and then redirect back to the same page showing some more fields - have you tried using the commandbutton with rerender attribute? Using rerender you can update a section of the visualforce page and add the fields you wish to show, something similar to what is explained on the link below: http://salesforce.stackexchange.com/questions/7497/hide-and-show-pageblock-on-button-click
Using rerender you can update a section of the visualforce page and add the fields you wish to show, something similar to what is explained on the link below:
http://salesforce.stackexchange.com/questions/7497/hide-and-show-pageblock-on-button-click