I recently configured my Squid server and have to tell u that I am new at this.
However, it looks like u have a few essential statements missing from squid.conf.
I may be wrong but, every documentation of squid.conf that I have encountered started with the following statements after
acl QUERY urlpath_regex cgi-bin\?
cache deny QUERY
acl apache rep_header Server^Apache
broken_vary_encoding allow apache
Also, u may need http_acces DENY all in u ACL statement.
I hate giving you this info, because I don't really know what any of these lines mean, but do know that I have seen them in almost every squid.conf file.
I found a website that was very helpful because it has a Squid Configuration Manual that tells u what each line in the squid.conf means. www.visolve.com
Hey, I know it is frustrating and wish u luck.
It took me 7 months, I'm not proud to say.
Hope this helps