Hello,
1) XStore Theme uses Visual Composer as the main page builder that’s why we did not test it with elementor. Can’t guarantee compatibility.
2) a. You can use image as breadcrumbs or header bg (Theme Options > General > Header settings & Breadcrumbs)
b. There is no option to use individual images for every product by default, only for simple pages. It’s possible to implement only by additional customization.
Regards