Many thanks to everyone who has offered advice.

It's funny that I got the "don't fix what ain't broke" advice now. When the derailleur incident happened, I posted here looking for someone to tell me it was OK to just true the wheel and ride (thinking then that only two spokes were damaged), and everyone seemed to think I should just replace those two spokes. I guess it looks different when I start asking about replacing all of them.

Anyway, I let out all the tension (before seeing FB's post #6) and without tension, six of the spokes have a pronounced elbow mid-spoke. I think I will try replacing them one at a time, because it was the lacing question that I was mainly worried about. I may also leave the spokes that aren't obviously damaged alone -- it's inside spokes that seem to be alright.

One thing I'll say is that this whole incident has given me a new appreciation for just how strong a bicycle wheel is. Like I said, the spokes bent but didn't break. Meanwhile, this is what happened to the derailleur:



FWIW, the wheel is a 32-spoke Open Pro with Ultegra hub.

Thanks again for all the help,