Is there a way to just go in and enter the correct paths in Wordpress? Or do I need to redo my galleries?
The paths to the images are hard-coded into the gallery XML files as absolute URLs so changing a path in WordPress would not help. The paths in the XML files would need to be changed. However, you could download them from your web server, open them all together in an editor such as Notepad++, do a global search and replace to change all the paths in a single action and upload them to their original location on your web server.
However, the watermark is not and the SV logo is now appearing. Since I have the Pro version that shouldn't be there right?
It sounds like your gallery is using the SimpleViewer-Standard 'svcore' folder.
Each time you upgrade WP-SimpleViewer, you will need to following the instructions for Upgrading to SimpleViewer-Pro.
SimpleViewer Support Team