$wysiwyg_text_area= new XoopsFormWysiwygTextArea(_MD_CONTENTC, 'content2', $value, '100%', '400px','');
$wysiwyg_text_area->setFonts(array('Courier New'=>'Courier New, Courier, monospace','MS Serif'=>'MS Serif, New York, serif','Verdana'=>'Verdana, Geneva, Arial, Helvetica, sans-serif','Tahoma'=>'Tahoma'));
$sform->addElement( $wysiwyg_text_area );
2.Right to left I think is only supported under iexplore, i¡ll try to add this on next bugfix version.
3.I have no idea how to select a default editor on newbb.