The simple answer is that being forced into slavery does not change the ethical status of my actions. I do not recognize the morality or legality of my enslavement, my actions are therefore morally exactly the same as a free person’s actions. I have the exact same natural rights as any other person, regardless of what the slaveholder or the slaveholder’s society claims.
I should therefore treat the slaveholder, the slaveholder’s agents, and the slaveholder’s family just as I would any other person. That is, I can ethically only respond to their actions or threatened actions. I can’t kill a baby just because the baby might grow up to be a slaveholder. I can’t kill someone who doesn’t threaten me with deadly force. In some slaveholding situations I can imagine that every adult member of the slaveholding class and every one of their agents is prepared to threaten me with deadly force at any time, in those cases it would be ethical to use deadly force in return. Under other slave regimes my use of deadly force would be justified in some particular cases and unjustified in other cases.
The fact that I am judged a slave by some people has no bearing on whether my actions are ethical or not. In most cases my ethical relationship to a person who calls himself my owner would be identical to my relationship with a mugger who holds me at gunpoint. I can use deadly force against a mugger in certain circumstances but not in others, the same circumstances would apply to a mugger who called himself my owner and imagined a more long-term mugging. I act to protect myself, if I can protect myself without deadly violence I have an obligation to do so. I also have a lesser obligation to prevent the mugger from mugging other people in the future, just as I have the right to protect myself I also have the right to protect others. But my use of force must be proportionate to the threat offered by the mugger.
Membership in a “class” of slaveholders is irrelevant. Such classes are human-created fictions. Every person is simply a person, their membership in a human-created class is irrelevant, what matters is their actions. If that person engages in unethical actions to you or others your responses to those actions change. But you are not allowed to kill someone merely because he pretends to be your owner, what makes your self-defense ethical or not is whether he threatens you with deadly force.