Hello,

Thank you very much for choosing our theme and for contacting us.

As for the language switcher please contact the plugin support or we can check as soon as your site would get online.

The header builder is an independent builder it does not depend on Elemetor.

You can create an HTML block with two columns and add into the mobile view of your Header builder. https://xtemos.com/docs/woodmart/html-blocks-2/#header_builder

Best Regards