i also have pf...was just diagnosed back in may (right at the beginning of my weight loss journey). i had been doing a lot of walking/jogging...more than ever before in my life and that's when i developed it. it was so bad at first that my dr. had me on crutches to take some of the weight off my feet.
i agree with many who've already posted...always wear shoes. i've discovered crocs as well and swear by them. i wear crocs/birkenstocks/danskos/brooks and the occasional pair of cute flats if i'm getting dressed up and won't have to be on my feet much.
for working out, i went to a local athletic store where the clerk looked at my feet and how i walk and recommended the brooks addiction. i absolutely love them and wore them everywhere (until i discovered crocs for everyday).
i do most of my exercise on the eliptical or in the pool now. i still like to walk with my dog, but i save the multiple mile treks for once a month now, instead of several a week.
one thing my doctor did say was to give my feet a complete rest when i'm having a flare up. i find that i can still swim when this happens, but the eliptical or the beaten path...no way
good luck to all of you!
ella