Besides disabling them from the Plugin manager area you could try hidding them on the RSTickets!Pro submission page. In order to achieve this you just need to edit the default.php file from components/com_rsticketspro/views/submit/tmpl/ and just before the last </script> tag add something similar to:
window.addEvent('domready', function(){ document.getElementById('editor-xtd-buttons').style.display="none"; });






