CommerceLab is a fraemwork we have developed that can hold many types of components. currently we are developing the ecommerce portion but we have many other types of components that will be housed by the same infrastructure.
We would say yes. The community at YOOtheme is thriving, their discord channel has enough people to help guide you. Also they have an extensive Youtube channel that can get you moving fast. We'd say give it a couple days you'll feel like a pro.
No. Your subscription covers support and software updates. Once downloaded, that version of the software is yours to use forever.
You will be notified before the end of your subscription to renew in order to continue to receive updates and support.
You can create article custom fields in Joomla then add them to a CommerceLab Shop product category and then in CommerceLab Shop manage the fields add your custom content giving you limitless options for each product. It'll all be there in your YOOtheme page builder for use.