Submit button disabled until the required fields are completed

This is not how WooCommerce works by default, and would take some custom code to do. We highly recommend contacting one of the services on our Customizations page for help if need be:

https://woocommerce.com/customizations/

It would also be great to have you add your ideas to the Ideas Board:

http://ideas.woocommerce.com/forums/133476-woocommerce

… which is where developers go to look for future plugin features and improvements.

I’ll leave this thread open for now in case others from the community would like to contribute.

Sorry I can’t be of more help here!