Hello,
1. Looks like there is our bug with settings. We will fix it in next theme update.
You can use this custom css code as a temporary solution:
.category-grid .categories-mask h4 {color: #f26107;}
.category-grid .categories-mask .count {color: #f2792e;}
2. Content of Shop sidebar can be changed in Appearance > Widgets. Read more – https://xstore.helpscoutdocs.com/article/48-widgets-custom-widget-areas
3. Please read our documentation – https://xstore.helpscoutdocs.com/article/66-mailchimp-form-custom-styles
Edit code of the form http://prntscr.com/jcnrtq > http://prntscr.com/jcns38
4. You can activate the main theme on site, but we recommend to use the child theme. Please read – https://xstore.helpscoutdocs.com/article/32-child-theme https://codex.wordpress.org/Child_Themes
5. Please read our documentation – https://xstore.helpscoutdocs.com/article/37-plugins-update https://xstore.helpscoutdocs.com/article/38-activation-and-purchase-codes
Regards