The main problem I have had is learning who he is. I have had to remove myself from the equation of action.
For example, I used to get upset that he eats everything that is on the floor. Now I understand he's a pig, and that's what pigs do. So I cleaned up everything that was on the floor, and taught him that "no" means he cannot nibble or bite on something else. Now he understands enough that if I say no from 10 feet away, he knows to stop, pull back and move on to doing whatever else he wants to do.
The other problem is taking him out in public. He really does not like getting picked up which I have to do to get him into my pickup truck, but I'm slowly trying to get him to learn if I pick him up, I'm not about to eat him. He just protests a little bit now, but he used to squeal and get extra defensive. I'm sure within a month he'll be fine though I am considering purchasing a ramp for him to get into the truck which eventually I'll have to do anyways when he's fat enough.
The other part with going out in public is I can't really leave him unsupervised for too long in a yard, and I guess that's the same with any other pet. For fear that he might eat something he's not supposed to and potentially die. This is probably more risky due to my job as a house flipper, because I work around debris. The good thing is it seems his stomach is pretty damn strong, he freaking chomped on a tiny bit of glass 2 weeks ago and I just about had a heart attack trying to get him to remove it...I was ready to take him to the vet if he acted abnormal through the rest of the day but he was perfectly fine. When he's chomped on other unhealthy things I couldn't get ahead of, like a metal bottle cap the other day, he's smart enough to know this is not a good idea and just drops it.
His loyalty is definitely to me, he follows me around as if I'm his father, but his loyalty goes out the window when grandma is around or any food is around.
I will say though, all the good stuff outweighs the bad. The other day, I took him to a restaurant to eat, and while I was wrapping up eating, he decided to get stuck in between the table/chairs on his leash. The leash which I lost grip of because...He REALLY does not like being stuck anywhere because it is another queue that he's about to be eaten by a predator. So he's squealing and causing a ruckus moving all of the chairs around while of course the other customers are looking and I'm just standing there saying "it's okay Phil, it's okay, it's okay" as I kneel down. Eventually he rattles his loud ass out of the chairs and comes to me. Clearly petrified & angry but does not attempt to run away like I'm sure a dog/cat would. He did have full range of the parking lot to run, even run to the street or other people. But instead he stayed next to me. That's one of the points when I knew I had the right pet.