Set different image sizes for stuff

Hi.
Currently my default image size and thumbnail size are perfect however, this has also changed my grid view size, would I be able to fix the grid view size to something smaller whilst keeping the default size for default view + single products pages the same?

Also, how could I stop default view from using auto-cropped images?

Thanks

https://www.ads-software.com/extend/plugins/wp-e-commerce/