That's good that you can pinpoint the triggers and reasons for your fears. You could actually say that you're far more conscious than your neighbour. He sounds more reactive whereas you sound proactive, productively exploring why you feel the way you do. Would be so much easier sometimes to be completely thoughtless and only choose to feel how we want to feel but then we'd run the risk of being someone like your neighbour and who wants a world filled with people like that, reactive and self serving.
I imagine you pretty much know everything that will trigger your neighbour. In other words you probably know him better than he knows himself. Imagine being bold enough to wake him up to how serious a problem he's got, 'Dude, do you realise how easily triggered you are? Do you think you should see someone about that? Do you recognise how unconscious you are?'. I do believe that would get his back up a little :) Wonder whether his wife is on the same page as you or whether she's on the same page as him. If she's a fairly timid person, it would be hell living with someone like her husband. Is he raising his kids to be narcissists or is he someone who regularly says to them, when they're trying to express themselves, 'I don't care, you'll do as you're told' or 'I don't care, don't talk back'? 'I don't care' is a terrible mantra to throw at a kid on a regular basis.
It's hard to do and can take a bit of practice but becoming a predictor or people's triggers can put us in a place of objectively observing them. What I mean is, taking the roof tiles as an example, if you can predict he'll react aggressively observe his behaviour, out of curiosity. Does he act like an animal, 'fluffing himself up' to appear bigger? Does he stand in an attack pose, like a guard dog faced with a threat? Does he spit as he speaks? How does his tone or volume shift?
Perhaps another thing to watch out for is...are you a bit of an empath? Do you feel for others or feel how others feel? For example, if someone's deeply saddened by an event, do you feel their sadness as if it is your own? Do you feel a heaviness in your chest while feeling 'choked up' on the verge of tears? If you are like this, chances are you're feeling your neighbour's anger. You're not just feeling how you feel, you're also feeling what he's feeling. That's an overwhelming amount of feeling. 'That's your anger, not mine and I'm not getting involved in that' can be one way of cutting an emotional chord.