Hello,
1) Page of category takes widgets from Appearance > Widgets > Shop sidebar, by default. If you want to change this, contact support of WooCommerce, maybe they will be able to sagest you some workaround. Additional customization is not included in our basic support scope.
2) If your footer was created using a static block, you can create a new static block with desired content and set it as “Use custom footer for this page” for Shop page (this footer will apply for Shop, categories, and single product pages) https://youtu.be/1Nu49dskD1Q
3) Breadcrumbs Style you can change in Theme Options > Header Settings > Breadcrumbs.
Regards