I do not have any experience with your valve problems or swelling, but I can tell you that compression socks are unbearable with PN. I have severe varicose veins, and have tried them, they increase pain and discomfort quite a bit. In fact, even jeans drive me crazy. The best thing about losing weight is that my pants are all really loose and don't bother me as much.
I would never attempt wearing any type of compression hosiery with this condition. I have to take even loose socks off after a few hours.
Walking regularly does seem to help some of my symptoms. I am tired afterwards, but generally find it improves my quality of life.