I'm sorry to hear about the pain you've experienced navigating your way through learning how to use our product. If it's of any consolation to you, our more systematic documentation is launching very soon. We're just making some furnishings so that its level of quality would be the same as the quality of the product itself.
That said, we do have an existing documentation that you can find here: https://theme.co/apex/forum/c/themeco/kb. It's not as detailed and systematic as our upcoming documentation but I'm hopeful you will find it useful for the time-being.
Regarding the issue of the video not stopping when the Modal Content Area was closed, I assume you solved it using the Responsive Lightbox shortcode (http://demo.theme.co/integrity-1/shortcodes/responsive-lightbox/). If so, it's a good approach. For more details about its configurations, here's the documentation for that: https://theme.co/apex/forum/t/shortcodes-lightbox/165.
But if you want to give the Content Area Modal another try, below is a quick tutorial on how to achieve your original goal.
Okay, to make a "played" video stop playing when the modal is closed, make sure the "Dynamic Rendering" option is checked as shown below.
This should solve the problem. If you have tried it and it didn't work, please do tell us so we can submit it as a bug/issue to our developers.
I hope this helps. Do know that you can always reach out to us when you have questions and we'll do our best to answer ASAP.