So I recently download the pro key for titanium backup (dont know why i didn't do this sooner). Right now it's uploading to dropbox but once it finishes and i flashed my new ROM, how would i download it from dropbox?
You would reinstall DropBox on your new ROM then just go to the backup on your Dropbox and find the file. Off to the right of the file you will see the circle with a downward arrow in the middle, click it. Then select MORE and then EXPORT. From the Export option it will give you many options to download it.