OK - attempting to reflash BB following this iClarified tutorial:
http://www.iclarified.com/entry/index.php?enid=12947
I notice that this tutorial has me doing the jailbreak and the BB change in the same process, which was what dhlizard told me at the very beginning was something to be done in 2 separate processes, and maybe was the beginning of my whole problem.
Anyway, jailbreaking/baseband-updating with 0.9.6rc16, phone shut off RIGHT at the "flashing BB (don't interrupt!)" part, after the progress bar hung there for about a minute. Can you believe it...
So then when I try redsn0w 0.9.6rc16 again the program closes itself after the first click! Won't stay open.
So I download redsn0w 0.9.b5 and try again (the phone is still in it's menu-able/non-wifi mode). Phone shuts off at about the 20% "flashing NOR" part - AND when I finally get the phone to turn on again, there is no apple logo.
I start the process again from the very beginning, but can't get apple logo back, just glowing black. I try the old 0.9.14b2 again and during the phase where all the code rushes up the screen it repeats "Please Wait" about 20 times, line after line, then starts spewing code again ...only to shut off. No apple logo.
redsn0w 0.9.rc16 starts to work again, so I give it another shot: while waiting for reboot redsn0w suddenly is gone.
I'll try again from the beginning...
btw - after these failures the phone is in a state where it doesn't want to turn on - sometimes I can jailbreak through it, sometimes not.