If I remember correctly, this should remove the toolbars on the tinyMCE:
function my_format_TinyMCE( $in ) {
$in['toolbar1'] = '';
$in['toolbar2'] = '';
$in['toolbar'] = false;
return $in;
}
add_filter( 'tiny_mce_before_init', 'my_format_TinyMCE' );
References:
https://codex.wordpress.org/TinyMCE
http://www.tinymce.com/wiki.php/Configuration
For the wp_editor, try applying these filter parameters onto your wp_editor() function.
Hope it helps.
** Edit
Also if that ['toolbar'] = false;
still prevents you from uploading galleries, you could just try this instead:
$in['toolbar1'] = 'undo,redo';
$in['toolbar2'] = '';
(Just add a couple of buttons like undo and redo to the top toolbar and remove the second). I’ve just tested this and it works with adding galleries.