Um, no state is going to let you kill people for damaging crops. An immediate threat, it's not. It has to be an immediate threat.
You can shoot someone to protect yourself. It's not black and white. Most likely, you will have to face a jury unless you shot them in your bedroom in the middle of the night. Don't bring your gun when you are trespassing. That just means whoever shoots you has less of a chance to face a jury.
You aren't a professional gunman. You carry a gun just in case. You are no good with it, trust me. Even people that are good with it shoot hundreds of rounds a week, or thousands. Police officers aren't good with guns. It's a last resort in any case. If you feel you need to carry a gun to ride your ATV, you aren't riding in a healthy area.
Until recently, Seal Team 6 used .38 revolvers. 180 ft# of muzzle energy or whatever. When you are good, you don't need sights. It's muscle memory. It's like pointing your finger and a bullet goes there. When a guy trains to shoot at the intensity that those guys have to maintain, you don't stand a chance. You bust into a room, you have an instant to decide what to do and even less time to take action there's no time for sights and 5hit. It's like the bullet comes out of your eyes.
What I'm saying is, you can buy guns, own guns and carry guns--but don't get outside yourself. When guns come out, you might get shot. You have a pipewrench at home, but you aren't a plumber. I have a miter saw, but I'm not a carpenter. I hired a carpenter and he did some finish work in 20 minutes that would have taken me two days and I would have made it ugly. Just understand that personal protection is an extreme situation. A handgun is an extreme tool. I would not voluntarily place myself in the situation where I might have to take a life, or get mine taken, over some pride.