If you like to have a (custom) mini richtext TV in your Template and use TinyMCE4 you can simply do this like this:
Input Type : RichText
Input Option Values : {"theme":"mini"}
My settings for the mini richtext TV I like are:
/assets/plugins/tinymce4/theme/theme.tinymce4.mini.inc.php
Content of: "theme.tinymce4.mini.inc.php"
<?php
$this->set('plugins', 'advlist autolink lists modxlink image hr visualblocks visualchars code media nonbreaking save contextmenu textcolor codesample', 'string');
$this->set('toolbar1', 'undo redo | formatselect | bold | link unlink code', 'string');
$this->set('toolbar2', NULL);
$this->set('toolbar3', NULL);
$this->set('toolbar4', NULL);
$this->set('menubar', false, 'bool' );
$this->set('statusbar', false, 'bool' );
$this->set('height', '100px', 'string' );
$this->set('width', '100%', 'string' );