Hi,
- To remove 'Category Archives', do the change in category.php file in the exported theme folder. In the file search for "Category Archives:" and comment or remove the following code:
<h1>
<?php printf( __( 'Category Archives: %s', CURRENT_THEME ), '<span>' . single_cat_title( '', false ) . '</span>' );?>
</h1>
- For header Image: one can browse the header image separately in each view and even set it according to the requirement. For this, all the three tabs are Desktop/Tablet/Mobile are available at bottom left corner.