I don't have much advice except talk to a local lawyer, to clarify what the laws that apply to you are, and what you can legally do. Just because discharge laws are liberal, doesn't mean you will be ignored.
I would not bother setting up a camera til I knew how things would go, and if someone would even look at a film.
I don't think 'following the law' is always going to be enough to get along with neighbors. If my shooting upset my neighbor, I could always go shoot at a friend's, or at a rifle range. Some people, that would just make them shoot off their porch all the more.
In most states, if a bullet leaves your property and does some damage, you will be liable. But as far as I know (which isn't very far) every single state and locality has different laws, and even more importantly judges, law enforcement, add their own point of view...but...
KEEP IN MIND...even deeds and covenants on certain properties can restrict shooting. There is also that.
TOO...sometimes it's a little complicated, where you live and what laws apply there. Your village or your township laws might apply.
A lot of times, I hear people say they can legally shoot as long as they are 500 feet from a dwelling, but when I look at the applicable law, the law usually doesn't say anything like that. Sometimes there is a limit based on how wide the property is, especially where there are lots of long, narrow properties.
My instructor told me, you have to shoot into an earth berm or something very solid (not a grove of trees, a target or into the horizon) or you will have stray shots, even with some of the least powerful weapons. When we shot, he set it up so we were shooting into the side of a hill. But he also told me most people don't follow even minimum safety rules.
I would try to not think about what the girlfriend said about the man. Sometimes people get revved up, and start saying things that aren't 100% true. Some people kind of brag about things as they think that makes them 'cool' or 'tough', or that neighbors will be backed off and not mess with them.
It is hard, though, we lived near a convicted robber. He stole my car and belongings. We moved away from there.