The DNS server DNS1 & DNS2 is the same as adding dns_nameservers the squid?
I am adding OpenDNS servers. to have more servers where to look and solve much faster names, according to some information that I found.
I created a template e-smith “10dnsnameserver” where this configuration “dns_nameservers OpenDNS-servers”
in tests evidenced good changes in the search or name resolution.
You don’t need it.
From the the original doc (squid : dns_nameservers configuration directive):
Use this if you want to specify a list of DNS name servers
(IP addresses) to use instead of those given in your /etc/resolv.conf file.
So, if you want to use OpenDNS servers, use them directly from the Web UI, and squid will use them 
Yes. I reversed yesterday test changes. Thank You @giacomo 