Spammers Hotlinking

I have found some spammer hotlinking to my images to get his site crawled, I have modified the .htaccess to attempt and serve his hotlinking domain with a warning but it does not work...

My actual .htaccess file is the one below (it was created by wordpress automatically):

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

I am adding these lines right below:

--------------------------------
RewriteEngine On
RewriteCond %{HTTP_REFERER} ^http://(.+.)?spammerdomain.com/ [NC,OR]
RewriteRule .*.(jpe?g|gif|bmp|png)$ /images/nohotlink.jpe [L]
------------------------------------

My questions...

I dont kmow too much what I am doing, following the tutorial here, http://altlab.com/htaccess_tutorial.html but the problem is that my .htacces already contains something created by wordpress that to me looks like garbage as I don't understand the meaning.

I dont know if I should add the lines inside the <IfModule mod_write.c> or outside them as I have done.

I dont know if it is ok to have two times Rewrite Engine On

PS: When I added the lines I describe above, my site also stopped displaying the images, I had stopped everyone including myself from hotlinking them. I only want to stop certain domain. or even better, my ideal solution is to WHITELIST my domain names (I have two using hotlinkg to those images), but I will settle for blacklist if it is easier.