Disable the navbar in a Bootstrap sub-theme
So to add this as an optional setting we can look at how it's done for other navbar variables. For example the navbar positioning which is on line 112 of that settings.inc

  $form['components']['navbar']['bootstrap_navbar_position'] = array(


Let's see where the variables you can select in that are referenced, such as fixed-top. It's referenced in html.vars.php where they implement the hook_preprocess_html() function to take that selection using theme_get_setting('bootstrap_navbar_position') and create some related variables to pass into the classes_array for the html.tpl.php.

So you can create a similar field with options like enabled and disabled and pass that on to the page.tpl.php using YOURTHEME_preprocess_page (which would probably go in template.php) to create a variable like navbar_on when it's enabled 

if (theme_get_setting('bootstrap_navbar_enabled') == 'true') {
  $vars['navbar_on'] = '';

 }


and then check in page.tpl.php to see whether or not that's true or not before printing the page.

     &lt;?php if ($navbar_on): ?&gt;
          NAVBAR CODE
     &lt;?php endif; ?&gt;


EDIT: actually maybe this is already in the theme, just not very clear
https://www.drupal.org/node/2287185