Your customers and potential customers will have a lot of questions about.
1. Your products
2. Your after sales service
3. Your buying process
4. Your returns process
5. Shipping charges and many other
You probably cannot answer each and every question and some questions will be repetitive. So, an FAQ page is important not just for SEO but also for making your website friendlier to your customers and improving your customer service efficiency by answering questions in advance through the website.
Other important pages
1. Privacy policy (you have customer data)
2. Blog (you are knowledgeable about your products, show it here)
3. Product comparison facility (to compare 2 or more similar products)
4. Add to wishlist facility (to choose products to buy in future)
5. Management profiles in About Us with social links (most of your competitors are hiding, stand out literally)