Hi,
1. Please don’t activate the mega menu feature for the mobile menu.
2. Maybe we have some bug with the categories layout, please send me FTP account & WP admin account via email roadthemez@gmail.com
3. You can translate theme by translate the language file in the “languages” folder
http://code.tutsplus.com/tutorials/translating-your-theme–wp-25014
4. Please add your custom css code into Theme Options=>Custom CSS.
Best regards