Nerves surely can regenerate when they are in the right environment, it is a very slow recovery though.
Numb areas does not always mean the nerves are completely dead, the soles of my feet were very numb, but over time i have regained a lot of feeling back in them and they are still continuing to recover in some small patches.
I am lucky enough to be able to live a normal life again, my PN doesn't affect me at all these days.
As far medication goes, i continued to use my pain relief as long as i needed to, then when i was ready, i stopped taken my Tramadol and haven't taken one since, i don't think it hindered my recovery but that's completely up to the individual, i believe it's about quality of life though.
Finding the cause is the biggest hurdle to jump.
good luck
Brian