Internal traffic should not go through ZS. unless is Wireless or Wireless -> Wired.
Even so, Proxy should not count. Where are u trying to access your sites from?
I have dns server on zs authoritative for home.domain.com and a few net appliances with http servers for admin/config with an entry on dns : appliance.home.domain.com
I can access http://spa.home.domain.com without any problems from my wireless laptop from both my routed or bridged wireless networks.
On the other hand havp project is kind of dead. I just added it for fun a few days ago and have no idea how to make it work with netflix. For real life stuff you should consider squid + some cache on ssd + squidclamav http://squidclamav.darold.net/