I have kept my pigs in close proximity to my chickens for years and haven't had any problems. I don't have guinea hogs though, I have a juliana and a mini/pb.
Our chickens FR during the day, but their coop and run are inside the perimeter of the pig/goat area. They are locked up away from the pigs at night, but can choose to be in the pig/goat area during the day if they wish (and often they do). We also feed all of our animals in separate areas to avoid mishaps.
It has worked for us, but we may have just been blessed with docile pigs. (or luck)
Our gilt actually formed a special friendship with one hen in particular from our very first flock. This hen preferred to lay in the pig house, and I'd often find her on a makeshift nest right beside our sleeping pig. They seemed to enjoy each other's company, and could be found milling around together and frequently with Piggy asleep on her side with a happy hen picking at her skin or dosing along with her.
I swear Piggy actually mourned her when she died.
Anyways, sorry for the digression... It can work (not saying in every case, but it has in mine), but remember that everybody still needs their own shelter and space at night and during meal times.
Another possible factor: we provide a big area for our pigs (between 1/4 and a 1/2 acre). I could see problems cropping up with pigs kept in a smaller pen with less to occupy themselves.
Oh, and we also have never taken chances with youngsters. Any chicks we've had have had to stay in the run until they've reached nearly adult size. In our case, this is precaution is due to aerial predators, but I also wouldn't trust the pigs with chicks.