I think love, in terms of romantic love, is finding the person who is the other part of you, it is a recognition. It is finding the one you were born for, your split apart. The other half of your soul.
If people who love each other are angry, I think many times it is a manifestation of fear. Fear that the beloved does not love, fear of disappointing the beloved, fear of having caused hurt, fear of losing the beloved, fear of not being good enough, fear of betrayal, etc.
I think you are not taking into effect that the people who can hurt us or who we can hurt are only the people we love. If a random person told me "I hate you." I might be annoyed, but not hurt because I do not know the random stranger and do not love them (except as a fellow human being). The only people who can really hurt me are the ones I love, because I am close to the fire, and sometimes sparks fly out and strike me.
People are imperfect beings, and we get angry, hurt, confused, etc. Ultimately, love is forgiveness and restoration. I remember the first time I told my mother I hated her (first and only time, thank goodness). I was a teenager, it struck my mother like a knife to the heart. The minute I said it, I was sorry. She forgave me, and the relationship was restored. This is love, it's not perfect, but it is unfailing. I often think of the parable of the prodigal son. He basically put his father through Hell, by leaving and degrading himself. The Bible doesn't mention it, but I can imagine how many tears were shed, how angry and wrathful the father might have been, how many sleepless nights he must have suffered, wondering where his boy was and if he was alright or even still alive.
The son came back and the father did not just welcome him back, but held a feast in his honor and restored the son to his former position. The son had planned to ask to be a servant. This to me means love- in all human relationships, not that there won't be all these terrible things, there will be because we are fallen creatures. But forgiveness and restoration are there if love is there.
I think confusion and chaos can come into love if there is a problem with communication. These things happen due to misunderstandings. When communication is restored, confusion and chaos cease. I know you are an atheist, but love to me in all relationships is akin to God's love. No matter what we might do, He always loves us, and we can always come back to Him and be restored in fellowship. So, even if there is a rift, if love is there it can be repaired.
I think it is simplistic not to think there is no suffering in love. There always is, if the love is true. It's not always perfect. Parents suffer when their children are disobedient, children suffer when their parents fail them, people suffer when they are hurt by each other. I realize you are not a Christian, but to us, the supreme example of love is also the extreme example of suffering. Christ is love, but also the Man of constant sorrow. If He did not love, He would not have suffered. I am not a Catholic, but I always liked the image of Christ with the bleeding heart. It reminds us that He loves and suffers even still.
The tolerance, respect, and kindness is just civility, not deep down love. Someone wrote, "The course of true love never did run smooth." I think this might be the reason why so many of our books, films, songs, etc. incorporate love and pain. Cruelty and wrath, chaos and confusion may happen. The question I would ask is, what were the causes of such feelings? If they are borne of hate, it is not love. But if they are borne of miscommunication and misunderstanding, these things could coexist with love.