Hello,
1) Negative margin for the row gave the problem on the mobile http://prntscr.com/vv6mkt
Also, I have created an example of the alternative way to make banners using row bg image below the existing banners.
Read about the responsiveness of the Revolution slider and edit it according to your needs for the mobile devices. https://www.sliderrevolution.com/faq/responsive-content/
2) We have added custom CSS to hide the breadcrumbs on the single product page. Check now.
3) You can choose the image proportions and crop option in Appearance > Customizer > WooCommerce > Product images.
Regards