I think you will be fine just saving the old config.inc.php file and replace the new one when done.
All I am saying is the config file holds most all the settings but some settings will be placed in the tables for use by threads and some settings will be referenced from the config file. They are still in the config file but that is for the control panel to use. When you select submit it will update what ever tables it is designed to do.
The only thing you may need to edit is the paths and or database info on the first 6 or 7 lines in the file if you use a different configuration.
If you read the transfer guide for dummys in the faq forum by Gizmo. You will see it is pretty much the same. move files and database to new server and edit the top few lines in the config file
Sorry going from memory is a bad thing. Gizmos transfer guide is HERE
not in the FAQ forum.