remove custom menus from main WordPress menu and show all plugin menu from right side or add another section of plugins menu.
means WordPress menus are posts, comments, pages, setting, tools that all show on same place but plugins menus like custom content type, galley, videos, jet-pack. e.t.c on the right side of the page.
and also add a functionality to remove unused menu from settings or add manually WordPress menus from setting. its quite difficult for non developers to add menus with functions.