>>2
Maybe so, im gonna be enabling a .htaccess referer bit
>>3
I would most likely say its the 1st one cept they just dislike the site, that version 1.5 apparantly, they had v1 too and it still had 4chan at the top. But im pretty sure anything i would do can just be evaded by rewriting just a small part.
>>4
IP ban does nothing when its multiple people doing it or their using tor. Proxy check might be an option but quite a few other legit people use it too...

And i really dislike captcha, wish there was some form that would be auto filled by the HTTP browser but not by a spambot