So I got all the other issues cleaned up and started my (modified version of tractor's) writeup for RHEL/CentOS, and let the install finish up, and I got this:
Creating domain vicimarketing.com...done.
Creating user email@example.com...done.
Creating postmaster alias...done.
Creating user firstname.lastname@example.org...done.
Creating user email@example.com...done.
Creating user firstname.lastname@example.org...done.
Setting spam training accounts...done.
Initializing store sql database...done.
Setting zimbraSmtpHostname for benjamin.vicimarketing.com...done.
Initializing logger sql database...done.
Initializing mta config...done.
Setting services on benjamin.vicimarketing.com...done.
Setting up syslog.conf...done.
Setting default backup schedule...Done
Looking for valid license to install...failed to install license.
Failed to install a license - this will prevent your server from functioning properly
Please contact Zimbra to obtain a license
Press RETURN to continue
I had copied the license the sales rep sent me to /opt/zimbra/conf/ZCSLicense.xml, just as I was instructed... but apparently that's not really where it wanted it... and I'm not sure how to add it on after the fact.