It is posible to avoid navigation div without creating a overriding page.tpl.php ?

Do I understand correctly that you're trying to show the main menu at the top of the page, above the logo and site name?

Disabling main menu in theme settings does not eliminate the #navigation element, which has the 3em height declaration. Even if you modify page.tpl.php to make #navigation conditional, you will end up with the top-margin: 3em on #main unless you override responsive-sidebars.css too. So if you never plan to use the navigation region, and you're satisfied with moving the menu block to the header, the easiest 'fix' is to override the css from

/*
 * Navigation bar
 */

@media all and (min-width: 480px) {
  #main {
    padding-top: 3em; /* Move all the children of #main down to make room. */
    position: relative;
  }

  #navigation {
    position: absolute;
    top: 0; /* Move the navbar up inside #main's padding. */
    height: 3em;
    width: 100%;
  }
}

to

/*
 * Navigation bar
 */

@media all and (min-width: 480px) {
  #main {
    padding-top: 0; /* remove padding if #navigation is not used. */
  }

  #navigation {
    display: none;
  }
}

I doubt this is the best solution, but it will work if you're looking to avoid changes to page.tpl.php.

Hope it helps. =)
Joy