Why does one suffer because of ignorance if ignorance is unintentional? It makes no sense that a person would knowingly choose to be ignorant of what causes them suffering, yet people suffer for "their" ignorance anyway. 

How is a person supposed to "freely/willingly choose" insight/knowledge if that choice is dependent upon already having some insight/knowledge? Are the persons choices before choosing insight/knowledge completely at random? Do people not have any freedom or autonomy?   

I think this may be another unanswerable question.
I don't know, I'm not sure what your background is -- I think the question would make sense, if you assume that "suffering" is a punishment imposed by God for sinning, i.e. for deliberately breaking (for "deliberately choosing" to break) one of God's commandments when you should have known better -- perhaps you're arguing that if you don't know then you are innocent and therefore shouldn't suffer.

I think a better analogy is something more like cancer, or any other apparent misfortune -- e.g. people suffer and die because they don't know how to cure it -- it isn't a question of whether it's fair (nor of divine punishment), it's a question of whether you've learned the insight and skill, maybe the habits, to undo the cause or to not do it in the first place.

Do people not have any freedom or autonomy?

I think they have a little. There's a sutta -- Chiggala Sutta: The Hole (SN 56.48) -- which suggests that we are fortunate to have been born human and in a time or place, where we can learn the Buddha's Dhamma.

Some people teach not only that the opportunity (to learn to practice) is rare, and nt only that we're fortunate to have access to the Dhamma, but also that it (i.e. the opportunity and the liberating effects) is a reason in itself for us to be happy.



Perhaps that's somewhat debatable though, a matter of perspective. Some people argue against the doctrine of "free will", saying that the physical world just does what it does and continues to do that, and that "people" are just conditioned i.e. that everything they do or think is just conditioned by one thing or another. I think that "free will" probably isn't a Buddhist doctrine -- but other people say (e.g. here) that an "exercise of free will" is "what makes Buddhist practice possible".