Woocommerce website linked to Ebay, Catch and Kogan through Omnivore

I have a Woocommerce Website which is linked to Catch, Ebay and Kogan through Omnivore. I would like some assistance improving the Woocommerce site without breaking any links to the marketplaces. The Woocommerce site uses the Astra Theme. I am not sure that I like the way it displays products and would like to change the look and feel and make it more attractive and user friendly. I could also use some help with streamlining the connectivity between Woocommerce and Ebay so that when I add a product to Woocommerce it lists correctly in Ebay. Some SEO and Marketing ideas would also be helpful.