Hello,
Thanks for the reply.
Let’s solve questions one by one and not mix a few together.
About images, you are using 3rd party plugins. Try to disable plugins that do not come bundled with our theme and check scroll/images then. If it was plugin’s fault, disable plugins one by one to find out what exactly plugin causes problems, then check the settings of that plugin.
Changes in the parent theme will be lost after update, so add your custom CSS code in style.css file of the child theme.
Regards