I'm so sorry you went through all that abuse. It's hard. My mom was never diagnosed as bipolar, but she was most definitely mentally ill. Her illness manifested as deliberately making me ill in order to garner support and attention from medical personnel. When that wouldn't work she'd beat, verbally & emotionally abuse. Other days she'd break my things - sometimes over my head. It doesn't have to be bipolar - I think any mental illness in a parent left untreated can be disastrous. She was supposed to take valium but never did. I think she should have been on something far heavier.
Having been in the mental health system myself for the past 12 years, I can tell you that medications aren't always the answer and sometimes make the situation worse, especially if there's a misdiagnosis. I was diagnosed as bipolar at the age of 16 and took medications for 9 years. During that time there were hospitalizations, suicide attempts, and health crises related to effects from the medications. Once I stopped taking the stabilizers & antidepressants my life started to come together again. My current diagnosis, CPTSD, was masking itself as bipolar. The extreme stresses caused by the trauma sensitized my brain to mood swings. Not dealing with the root issues of abuse left the trauma time to do some extra damage. I'm no longer on meds and am at my most functional. It's like someone threw some oil in my turbulent waters. The real issues are finally (albeit extremely slowly) being dealt with.
During this entire time, my parents separated. My dad went through a very predictable situational depression. Because of my bipolar diagnosis the doctor prescribed him lithium and said that he was bipolar, too. This highlights a very interesting flaw in the current practice of diagnosing family members based on genetics - if one family member is misdiagnosed, it's possible the rest have been misdiagnosed as well.
Bipolar rage isn't always directed outward. The sufferer can take it out on themselves in the form of self-injury and suicide attempts. I think a child witnessing their parent suffering from this type of rage can be traumatized as well. Either way, the root issues need to be addressed so the child has a decent chance of growing into a healthy person.
Blame it on me, but know that I won't regret one iota.