stock rom; you'd have to have usb debugging enabled to use adb while booted into the rom. if it was working and just shut down, and won't reboot into the rom... it wants /data and /cache wiped probably. but the only way to do that is with recovery or adb.
did you ever have a working recovery on the phone (the only way to tell is to have booted into it at least once)? or was it just installed and assumed that it would work?
how was the recovery installed?
and adb says device offline, while booted into the black screen which should be recovery? or when it boots past the android logo and goes black? or both?
If the recovery didn't install right, it shouldn't recognize the phone at all while booted into the broken recovery. If it did install right, clockwork should automatically allow adb access, even if it's an older version with the wrong kernel drivers for the screen.
to see if clockwork is indeed installed and working (even though you can't see it), press the back button a few times, after it's been booted into recovery for at least one minute, then press the camera key, then the menu key, then the home key. One of those last 3 is the select button, depending on which version of clockwork is installed.
If the phone reboots after those button presses, the recovery is installed, and you just can't see it. In that case it's possible to make it wipe /data and /cache by blindly pressing the right keys in order. Should that be the case, I can probably list what order to push buttons in.