the correct command should be:
/sbin/e-smith/db configuration set squid status enabled
note you missed the word status in your command!
I'm not sure how to go back... maybe
/sbin/e-smith/db configuration delprop squid
followed by a "signal-event post-upgrade" and "signal-event restart" so template are rebuilt.
anyone can confirm this BEFORE FreakWent test it ?
EDIT: FreakWent: because you have all information requested to go back to previous state, you can issue a long db command with all those parameters... or use one each time.
/sbin/e-smith/db configuration setprop squid
EnforceSafePorts no
SafePorts 21,70,80,81,119,210,443,563,980,1024-65535
TCPPort 3128
TCPProxyPort 80:3128
Transparent no
TransparentPort 3128
access private
status enabled