Hi, Gregor!
Yep, RewriteBase is the path to your blog root (I think It’ll work without it too).
The love.php file can be anything, I just happened to have a file called that. You can use any file that you have or creates – the interesting part is to see that the link is rewritten.
Phpinfo
<?php
phpinfo();
?>
will show more interesting stuff than an empty file.