Project transfer: If you still have the projects in your Documents\Shapespark folder, you can copy them from there and upload to your new account. To logout from you test account to be able to login to your company account, either delete the test account (https://cloud.shapespark.com/#settings) or remove a file C:\Users\YOUR_USER_NAME\AppData\Roaming\Shapespark\auth and restart Shapespark.
Custom branding: you can show your company logo in the upper left corner of the viewer and hide the Shapespark logo in the lower right corner.
Account rename: If this is still a trial account, the easiest way would be to delete it in the https://cloud.shapespark.com/#settings and create a new one with a different username and email. If this is already a paying account, please send the current and a new username and email to firstname.lastname@example.org and we will update them.