We are pleased you like the theme and going to purchase one more license.
The brand is a Woocommerce attribute. It can have any title: Author or Admin – any, however, its functionality would be as the attribute and it will be shown on the product page if you assign to a product and the brand page would be empty if you do not assign any products and as I understand it would be useless.
IF I follow your idea correctly you are searching for a custom post type to show, if so, you can consider Projects and rewrite the theme with Loco as per your needs.
The second question is not clear enough, could you please send us the screen or a sample of what you want to implement?
i think attribute suits better (i want to use it for author’s name).i dont know if u have anything else to suggest instead of that.but i need authors name to shown below books title and also be searchable (think attributes is fine with that).
As concerns the second question we need to include books extra title (subtitle) as an extra field below main products title (i m attaching a photo)
You will need to add this title and sub-title in the short description of the product page. Woocommerce does not provide the option to add additional titles and sub-titles to the product page and our theme does not have either.