My struggle with back issues started almost 20 years ago, with a couple of broken lumbar vertebrae and a fusion. A few years later this was followed by a couple of blown disc in the same area, and then a few years after that, an auto accident left me with some cracked cervical vertebrae and fusion. So, I can certainly feel your pain! I now have chronic flank pain, as described by my PM Dr., that is nerve pain in the intercostal region.
As for your questions:
1) I have never had a successful cortizone injection, at least in my back. I had an intercostal nerve block done a few months ago that gave me about 3 weeks of decent relief, but that was all.
2) I have not had too many (5 or 6 total?), especially since my lumbar fusion made a large bone mass down there and makes it difficult to get needles in there. The last L5 block they tried they had to go through the tailbone - that freakin hurt!
3) I never had surgery for disc issues, but I know that times and procedures have changed since my issues in the mid 90's. I wouldn't look at it as a bad thing if it is proposed.
4) I don't really know the answer to this one, but my guess is that the cure is it "blowing out".
5) Nerve pain is the worse pain for treating I have ever experienced. I am going to start sounding like a drug rep here, but I have found 10x more relief with Lyrica than with any narcotic. My "normal" is far from normal, but we have to adapt, and I am sure you understand that. I accept that I am never going to be 100% pain free, but anytime I find something that makes my days liveable (Lyrica), I certainly appreciate it!
Take care of you, and please keep us posted on your progress!