Unhappy [Q] Wiped /sdcard and /system - only have CWM now. How can I proceed?

I had an older custom ROM and CWM 6.0.10 and I wanted to update to a newer 4.4 ROM (Omni) so I booted into recovery and proceeded to do a factory reset along with a format of /sdcard and /system. Now when I reboot, I enter recovery automatically.

I managed to push the ROM .zip to the phone using "adb push ROM.zip /sdcard/ROM.zip". The problem is that when I try to install from zip (withing CWM) the install fails with this message:

SymlinkingApplyParsedPerms: removexattr of /system/addon.d/50-hosts.sh to 0 failed: Operation not supported on transport endpoint
script aborted: set_metadata_recursive: some changes failed

set_metadata_recursive: some changes failed
E:Error in /sdcard/omni-4.4.4-20140825-maguro-FML.zip
(Status 7)
Installation aborted


I'm stuck here and I'm guessing that I shouldn't have formatted /sdcard and /system as the directory "/0" that the error message refers to isn't on /sdcard anymore (it used to be). Not sure what to do at this point.

I've tried flashing TWRP, but fastboot waits forever with a "<waiting for device>". I thought TWRP might let me sideload the ROM (I was thinking that this manner of installing might create some default partitions on the SD card, as needed.

I welcome any suggestions. BTW, this is all on a Galaxy Nexus GSM

Adrian