A human-like robot suffers from sexual, emotional, and physical abuse from their romantic partner/owner. This is depicted graphically in episodes 4 & 5. Not necessarily domestic violence, but it should also be noted that there is a character who doesn't take no as an answer when asking the protagonist out, although he never physically harms that person.
An amputation is never shown, but several characters have missing limbs and use prosthetics. The protagonist has a prosthetic leg, but it is explained in ep. 88 that it was not amputated. During ep. 12, there is a decapitation. During ep. 59, someone's arm is torn off, although the process is not shown and only the aftermath is.
One of the main characters is repeatedly gaslit into thinking things are his fault, especially towards the beginning on the story. This is not the only example, but it is the most obvious one.
There is mild physical restraining. However, a recurring topic is robots being trapped or restrained in their body, unable to act against their owner's wishes.
In a way. One of the main characters is considered different or weird because they are a robot that has human-like thoughts and emotions. He is also seen as violent, because he has the capability to injure people, while the other robots don't.
A child struggles with gender dysphoria in ep. 26. Later on, a robot character is shown struggling a lot with the fact that he is a robot and not a human.