Once I open an eStore can I link it to my eBay account (for things like feedback or Final Value Fees or FVFs for products listed on eStore)?
Your eStore will be completely independent of your eBay account. Reviews and feedback on your eStore can be provided by customers through the ‘Write a Review’ or ‘Important Links->Testimonials’ options provided. Since the eStore and your eBay accounts are separate, eBay cannot levy any FVFs for sales made on the eStore.