Hi,

1) Main category can be edited from Page Builder > Content > Category X. The image of each category is set as a background image of the first row.

http://i.imgur.com/nEqrGn7.png

2) Unfortunately, you cannot insert custom links in place of categories. You will have to use the HTML menu type and create the menu manually.

3) Sticky sidebar is enabled from Theme Settings > Style > Content Wrap

http://i.imgur.com/msSeO9z.png

Sticky header is activated from Theme Settings > Style > Common.

4) In this layout of the brands menu, you cannot display images.

5) OpenCart does not support svg images to be used. You will have to manually add the logo in catalog/view/template/common/header.tpl.

6) Here is a CSS fix for the compare table width problem:

@media (max-width: 768px) {
  .tb_page_product_compare .description {
    white-space: normal !important;
  }
}

Add these styles from the Theme CP > Theme Settings > Custom > Custom Stylesheet text field.

BR,
ThemeBurn team