1. Can you try recreate the thumbnails using this plugin https://wordpress.org/plugins/regenerate-thumbnails/ make sure the image sizes are correct in Appearance -> Customize -> Woocommerce. In the new update woocommerce moved their settings to customizer, maybe that cause some issue with the image sizes, I suppose.
1. What browser do you use when see the pagination issue? Can you try another browser or PC?
3. It’s not theme issue, it’s how Visual Composer works. Row is not full width while loading script. If you don’t like this try to speed up the site, then script will be loaded faster and you won’t see this effect. Provide contact plugin author, maybe they have any other solutions for your but I’m not sure.