My heroin-addicted dad committed suicide when I was 17. Believe me, you will not feel ANY satisfaction if that did in fact come... you might think you will but you won't. I thought I wanted him dead, out of my life, I thought he didn't deserve to live after all the hell he put my family through. Turns out I didn't once he was gone. My dad did terrible, horrible things. Broke my family apart, treated my mom, sister, and I terribly. He would lie, steal, and drive with my sister and I while high. He would abuse, neglect, and use words as a weapon. I found him dead in our apartment (my mom and sister left 2 years before), I did not feel one ounce of satisfaction. I felt panic, grief, guilt, and abandonment, even though I was not the cause. You would not be the cause of his suicide, therefore nothing "legal" can happen against you. Suicide is really their decision and it's based on a ton of factors, not just one thing happening. When someone commits suicide, they are usually deeply depressed for a very long time beforehand.
You should check out the "Family and Friends" section on this forum. You will find a lot of help there to find your own peace and learn how to focus on you and not the addict. Only you control your life and your happiness, no one else should.
I believe it is fully within your right to tell him how much you hate him, how you hate his actions, how you hate his lies and it might even make you feel a bit better because we generally live in such silence. It is also fully within your right to cut off all contact with him and not feel guilty about it. He's manipulating you and making your life hell, so it's your choice to put all the focus back on you and not on him. He should not have a say in how happy your life is or how fulfilled of a person you should be. If you believe that you would be better off not talking to him, then don't. It's a healthy choice. Don't expect him to all of the sudden change though, he will not get clean because you said this or because you have cut off contact with him. He must make his own choice to get clean. Nothing will change his mind until he hits his "bottom." Remember that you didn't cause his addiction, you cannot control it, and you cannot cure it.
You should really look into codependent behaviors. There is a lot of information on the Family and Friends section about codependency if you would like to read more.
I'm 20 now, it gets better once you get out of the home with the addict. In my case, I didn't really have to leave the home...he left me.