What you did is one of the ways of overriding default templates.
If you copied the files it will be used instead of the default ones, so you can freely customize it (however I suggest not to remove the action or filter hooks)
But whe you copied the single-event.php you should also copy the content-single-event.php cos these two work together.
The other way of customization is by adding / removing actions hooked to specific do_action functions in template files.
Like this:
// EM remove template actions
function df_add_and_remove_actions() {
remove_action('em_before_main_content', 'em_breadcrumb', 20);
remove_action('em_get_sidebar', 'em_get_sidebar', 10);
remove_action('em_before_main_content', 'em_output_content_wrapper_start', 10);
remove_action('em_after_main_content', 'em_output_content_wrapper_end', 10);
remove_action('em_after_loop_event_title', 'em_display_loop_event_meta', 10);
}
add_action('wp' , 'df_add_and_remove_actions');
// Do something in a template action
function df_display_something() {
// do something
}
add_action('em_after_loop_event_title', 'df_display_something', 10);