If I want to change the folder location of STM, can all the corresponding necessary settings in STM be changed manually, or is an uninstall/re-install of the program necessary?
You would need to uninstall/reinstall. When you uninstall, the program will not erase the backup copy of your default (registered) xls file. You will need to move that backup file to your new directory and open it from there. At that point, the program will ask you if you want to restore the file. Click yes/ok.
Understand that all of the picture/sound file selections are stored as absolute references, so you will need to re-assign them (for each saved tournament).
I would recommend against doing this unless you really need to.