Looks like I'm still stuck at step 6. After running ADB reboot recovery, the tablet reboots and I see the dead Android with the red triangle. So I'm guessing Recovery didn't get flashed right.
So I rebooted it again. Ran the Nexus7.bat. It boots to Fastboot okay, and seems to be successfully after pressing enter a couple times. But ADB reboot recovery results in the red triangle again.
Android: Nexus 5, Nexus 4, Nexus 7 2013, LG G Pad 8.3 LTE, Nook HD+
iOS: iPhone 5S, iPad Mini with Retina LTE
Windows: Lumia 521, Venue 8 Pro