I lived on a farm for part of my life when I was younger. We had chickens and pigs, and housed them separately. In the rare instances when a chicken managed to somehow get into the pig's space, it got eaten. I would absolutely not trust pigs around chickens. Maybe some of them could be safe and wouldn't do anything, but all it takes is that one pig that develops a taste for chicken, and you have disaster on your hands.
Absolutely! And they may still try, despite their size! Without meaning to, too. One time a few years ago I was sitting with my small handful of pet chickens, it was summer and I had shorts on. My attention was on the chicken in my lap, so I didn't see that another chicken had taken an interest in something on my leg. I was vaguely aware of her pecking my leg, but chickens peck things out of curiosity, and it didn't really hurt, so I ignored her. Sometime later it started to sting a little, so I looked down to find the chicken's beak covered in blood, a trickle of blood running down my calf, and a pretty sizable hole developing into my skin where she was pecking!!! I'd nicked myself earlier and had a small scab there, and apparently she started investigating the scab by pecking, pecked it off and saw blood, then went all savage on me, but the tough leg skin in that area isn't sensitive enough for me to have felt much until it started looking quite gruesome. She was going for meat at that point and if I hadn't stopped her and walked away to patch up my hole, I bet she would've kept going until she was ripping hunks of meat off! Chickens have been known to cannibalize each other like this, or anything else they can get their beaks on. It's like something in their brain flips when they see blood. That thing with the bull seeing red? It's not the bull, it's the chicken!