Yes, WooCommerce is integrated and fully functional in SaasLand. You can build your own store using SaasLand.
Yes, SaasLand is compatible with Gutenberg.
Yes, SaasLand is compatible with WordPress 5.0 and higher versions.
Rogan WordPress theme comes with “Elementor” which is a very advanced, drag-n-drop page builder. For Elementor related issues, you may check their support: https://elementor.com/support/
According to Envato’s licensing, you can use SaasLand or any other theme on only one website. If you want to use it on multiple websites, you must buy multiple licenses.