Hi,
Professional counselors would say that if someone dislikes you without an apparent reason, it's most likely they feel that
you dislike them or they in some way feel threatened by you, or you remind them of traits they don't like in themselves.
Many of the advices suggested here have been "tit for tat" and "get even" tactics. I disagree strongly with such behaviors, which will only harden attitudes and likely make the situation worse.
The solution is to make the person
feel good about himself -- through praise, having him share in a project with you, self-depreciating behavior (by you), etc.
You have only been on this land a little more than a year. In "the country," it usually takes much longer, a few years at least for newcomers really to be "accepted". Think of those who live in the areas as like the roots of the oak trees, deep.
It appears also that you have started doing fairly major (and perhaps to him expensive) projects, and maybe he feels that his own space and lifestyle is somehow threatened, or may be in the future. He may feel you are "superior" to him financially, or in some other way.
Perhaps when you were told the neighbor complained about the "green vapor," you could have asked him to come and show you exactly where this noxious gas was, because you sure don't want that kind of polluition, and appreciate his pointing it out.
I am not saying that he or you is right or wrong. But when you say "I am asking advice before I strangle this guy and serve jail time. Yes, I am at that point," you obviously are not in control of the situation. I doubt your wife would agree on a potential solution that would earn you a jail term?
If you expect to live next door to this person with your parents for the next 10 years or more, you need to reach some accommodation. For you to steel yourself and "pay him back" for every deed of his, will only make life a horror for all of you. Have your wife cook up as meal, or bake some cookies and take them over and give them to him, say she "made too many" and give them to him.
You need to give him an impression of you that is somehow positive, and elicit behavoirs in him beyond angry glares from behind the curtain.
Most people cannot remain angry after receiving heartfelt gifts. It is embedded in human nature to repay a gift with a gift, kindness with kindness. It is the easiest way to dissolve anger and discord.
I recommend the book "Make Peace with Anyone: Breakthrough Strategies to Quickly End Any Conflict, Feud, or Estrangement," by Dr,. David Lieberman. He has dozens of insights and superb tactics that will surely help you find a favorable end to these conflicts. It may take some weeks, several interactions, but you need to work toward solutions, not embittered "paybacks."
Link to Amazon
If you are actually convinced that there is no chance whatsoever for a positive resolution resulting in a happy and peaceful life for you AND him, then move.
There is an old saying in the East, "When looking for a new home, first find good neighbors." I always check into the situation of neighbors, especially in rural environments. We lived in rural upstate New York for more than 20 years. We did have various incidents with neighbors similar to what you describe. We sucked up our ego, granted real respect to those who were there before us, and found a way to live in peace.
All the best.