If my experiences can help others... (And thanks to the OP, this helps me to, it reminds me to take the time to re-asses my situation as well)
I myself have a 19 year old and we don't talk much, he's very focused on what he does, good and bad. I will talk to him when he wants to be talked to. He holds a part time and goes to college, I pretty certain he doesn't do drugs, he's drank very little alcohol and I don't believe he drinks at all at this time. Overall he's well ahead of where I was at 19 (I had a full time that lasted 13 years but I partied every-night, lived the saying was work hard, play hard). My wife talks to him more but she would love for him to be a social butterfly. I have to let her know how I was, how a lot of males are at this point in their lives. I feel I'm very ok giving him the room he thinks he needs and monitor him from 10,000 feet the overall path he's going down. He doesn't really raise his voice, that said an outburst from him would not foster a nuclear showdown with us. Conclusion today for him - Satisfactory.
I have a 9th grader, in 5th and 6th grade he was very hard to deal with, nearly impossible. He had a real temper, had things going on upstairs, threatened suicide, couldn't focus. Instead of going with the 70's response, "he's a kid growing up" and leave it at that, today we have to take him to specialists. What is wrong with him? Obviously something is wrong with him! Medicate. Consoling. I was always about 50-50 at best in the support of that effort, the wife drove this. In 6th grade we pulled him out of school to home school, that was just a wee better at that time, his focus was just so short then. He went back to public in the 7th grade and there was a huge change, since then he just gets better and better, what do I attribute this to? The 70's response, "he's a kid growing up", parent over-reaction. Now in 9th, his anger is way way down, he always was very loving for a boy when he is in a calm state. He is the kid that speaks back to his parents, just tells me I have more work to do. Conclusion today for him - Steady Improvement.
These kids are their own people, I work on molding to make sure they aren't jerks and exhibit good values to outsiders. I don't believe in the Black and White Book of Raising Children at all and believe way more in a natural understanding of things. When they are jerks to me, I treat that as schools in session, they are failing and need some advice. I don't take it to personal, as when I did it to my folks it wasn't really personal to them, it was personal failure in me, I didn't want to be bothered on their schedule. Ultimately I felt bad some time after my outbursts, not always going back and apologizing either, but I knew. That "I knew" to me was the key growing out of it.
So my goal is to raise nice people. I figure in their mid to late 20's I can get a fairly final grade. Their greed will drive how financially successful they will need to be. So I let my 19 year old have all that room he needs, he's meeting his responsibilities and we are still working on him being a nice person to outsiders, he's too short and direct. We pick and choose our spots, we have 6 or so years left. The young'n is too early to tell, personal hygiene would be nice! Raising is just as much a test for the parents patience and understanding. I want the kid to walk away from the problem, calmer if possible and hopefully something for them to think about. What happened? And how to make it better? Not just me telling them straight up Step 1, this. Step 2, that. IMO they have to get it for themselves for it to stick. I didn't have perfect angles and I'm no beacon of perfection myself.
To the OP: If they are raging on me, then they aren't ready for 100% outsiders. This is not the time to throw the towel in and them out. The cheese isn't ready! That said it's a two way street and if they are set in staying out, then you make a plan for that scenario to work and for them to grow.
The day I had my first child, was the day I really knew I had an Achilles heal.