Use single profile on checkout from cart
Just so you know, there's two extensions currently under development for CiviCRM, and specifically that integrate with CiviCRM's Event Cart feature, that might meet some of your needs. They're under active development, and you can check them out on CiviCRM's GitLab. 

boxoffice: Provides a lighter workflow for the CiviCRM Event Cart. Designed for a ticket box office (ex: where you do not need the names of other participants).

eventpack: Provides a way to bundle events together (at a discounted price) in the CiviCRM Event Cart (and the Boxoffice extension).