[soxfan]

try
zmprov -l modifyServer myserver.mydomain.com +zimbraServiceEnabled mailboxd

Well re-running install.sh had my system back to normal, but in the interest of trying to mark this thread as SOLVED I decided to break the system again by making a change so that I could try this out.
This time when I ran the 'zmprov' command, adding the '-l' option, I did not get the "connection refused" error, however, it also did not fix the problem. Still could not get into the admin console or the web client. Running 'zmcontrol stop'; 'zmcontrol start' yielded the following:

zmcontrol stop
Host myserver.mydomain.com
        Stopping stats...Done
        Stopping mta...Done
        Stopping spell...Done
        Stopping snmp...Done
        Stopping antivirus...Done
        Stopping antispam...Done
        Stopping imapproxy...Done
        Stopping mailbox...Done
        Stopping logger...Done
        Stopping ldap...Done
[zimbra@myserver ~]$ zmcontrol start
Host myserver.mydomain.com
        Starting ldap...Done.
        Starting mailboxd...FAILED
sh: start: command not found


        Starting logger...Done.
        Starting antispam...Done.
        Starting antivirus...Done.
        Starting snmp...Done.
        Starting spell...Done.
        Starting mta...Done.
        Starting stats...Done.