I create a new topic, as you wish. ;)
I needed to modify a little bit 2 of your plugin files in order to have a full translation :
line 111 & 163 :
esc_attr( 'Save Changes', 'kc-settings' )
esc_attr( __('Save Changes', 'kc-settings' ))
line 568 :
<?php echo __('Main','kc-settings'); ?>
Keep up your fantastic work on this plugin !