UPDATE/RESULTS
After several days of my car sitting BACK at the dealership, (the mechanic involved kept working only half days) they decided to contact GM. The Ford mech's surmised that "your radio just must have coincidentally acted up while in our possession.
Seriously?
So after taking it to the GM dealership, they put it on diagnostics, and simply reprogrammed the radio.

SO, after spending almost $200 getting new sway bar links, and another $60 getting my radio reprogrammed, I've got my ride back in my possession.

I suppose the lesson here is never take advantage of a dealerships "good will offering" AND never, EVER take a Chevy to a Ford dealership under any circumstances.

 

How would you change the battery without the radio going into 'lock mode'?

 

It doesn't go into lock mode.....if you tried to use another radio ,that radio would be locked as it hasn't been "married" to your car....its all in the programming..theft deterrent, makes the original radio unusable if removed and used in another vehicle....

 

btw: after having my radio reset by the chevy dealership, now my ST does not display, and the sound quality isn't as good.

 

Kind of sounds like the Ford mechanic needed a new radio for his Chevy! I wonder if the is a traceable serial number on the radio?
In any case if you paid the Chevy dealer to do the job they should do it properly...Take it back if you can afford more days in the shop.