It is soooo true about the physical therapy - once I had a good therapist who understood the CRPS a bit things progressed much better. That was a great and informative post Catra
I can't add much exercise-wise to Catra's post, but one thing that really helped initially was a series of general body exercises 'for those confined to bed' - I think it was on a diabetes site!! I started them after I had been having a particularly bad flare for over a week, and I literally couldn't get downstairs and struggled to get out of bed at all. I knew the longer I stayed inactive the worse things would get, so I started doing the page of exercises every day. It really helped, and within a few days I was feeling a bit better and able to do a little more. Daily exercise of some kind is hugely important in CRPS, particularly on the bad days

Core body strength is vital for everyone, but particularly if you have any kind of weakness that affects your walking.
The other thing that helps with the CRPS I have in my feet is walking about on carpets barefoot. I find the extreme of temperature walking on a hard floor does me no good in the long run, but carpet is fine. Walking barefoot makes your foot muscles do all the jobs they were designed for, and really helps with strengthening and stability. Wearing slippers or shoes all the time weakens some of the muscles in your foot because you don't tend to grip with your toes in the same way you do barefoot. It's worth a try.
I also have a Wii Fit system and I do games like the balancing ones - ski slalom lol, and balance board - they are really good for strengthening and balance, and my physio thinks they are excellent for CRPS in particular because the fun visual element helps to distract you from any discomfort or learned guarding behaviours. I position mine on the floor near my sofa and sideboard so that I have something to hang onto if need be!
Good luck,
Bram.