1) a) To change the categories images go to Products > Categories > edit the category and upload category thumbnail.
b) To change the category design go to Theme Options > E-Commerce > Categories
c) To display categories on Shop page go to WC > settings > Products > Display
2) To change the breadcrumbs image go to Theme Options > General > Breadcrumbs > upload breadcrumbs image. To change it for shop page only edit the shop page and upload featured image for your shop page, it will be used as the breadcrumbs image.
3) You can find what presets are imported at Massive panel, for example http://prntscr.com/gvo6yt and then find it in element settings http://prntscr.com/gvo6li