Done. In ajax.php I made some changes. Here how:
$chars = 'абвгдежзийклмнопрстуфхцчшщъьюяАБВГДЕЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЬЮЯ';
$tags_array = explode(',', $content['post_tags']);
$stripped_bio = strip_tags($content['about_the_author']);
$stripped_content = strip_tags($content['post_content']);
if ( !empty($content['post_title']) && str_word_count( $content['post_title'], 0, $chars ) < $min_words_title )
$error_string .= 'The title is too short<br/>';
if ( !empty($content['post_title']) && str_word_count( $content['post_title'], 0, $chars ) > $max_words_title )
$error_string .= 'The title is too long<br/>';
if ( !empty($content['post_content']) && str_word_count( $stripped_content, 0, $chars ) < $min_words_content )
$error_string .= 'The article is too short<br/>';
if ( str_word_count( $stripped_content, 0, $chars ) > $max_words_content )
$error_string .= 'The article is too long<br/>';
if ( !empty($content['about_the_author']) && $stripped_bio != -1 && str_word_count( $stripped_bio, 0, $chars ) < $min_words_bio )
$error_string .= 'The bio is too short<br/>';
if ( $stripped_bio != -1 && str_word_count( $stripped_bio, 0, $chars ) > $max_words_bio )
$error_string .= 'The bio is too long<br/>';
if ( substr_count( $content['post_content'], '</a>' ) > $max_links )
$error_string .= 'There are too many links in the article body<br/>';
if ( substr_count( $content['about_the_author'], '</a>' ) > $max_links_bio )
$error_string .= 'There are too many links in the bio<br/>';
if ( !empty( $content['post_tags'] ) && count($tags_array) < $min_tags )
$error_string .= 'You haven\'t added the required number of tags<br/>';
if ( count($tags_array) > $max_tags )
$error_string .= 'There are too many tags<br/>';
if ( $thumb_required == 'true' && $content['featured_img'] == -1 )
$error_string .= 'You need to choose a featured image<br/>';
Hope this can be implemented in next release.