blaze will take care of any error handling issues there might be. It was made with developers in mind, as well as usability and visitor comfort.
The debug mode will enable full error output (powered by Whooops) and make all errors that occur readable to you. That's one of the reason why the debug mode should definitly be disabled when your site goes to production. (It will also affect asset handling and some other stuff...)
The fully readable error pages will also be visible to any logged in admin user, even if the debug mode is disabled.
When you disable the debug mode and enable public access, blaze will not show any occuring error to your page's visitors.
If an error occurs that will not cause your site to fail completely, it will just send a mail to the mail address that has been setup in the backend and show the page. If there is a fatal error, blaze will also send a mail and inform the visitor that the admin of the page has been informed about the error.