1) Why was Frederick nervous about the auction? Well the reason why Frederick was nervous about the auction because he was being sold to Master Andrew, now Master Andrew is a cruel person, "there was a horrid dread falling into the hands of Master Andrew". (Douglass 80) He was know to be a mean and cruel Master.
2) Master Andrew was a mean and cruel Master as I said before. Master Andrew was so cruel, he beat up Frederick's brother to death until he was on the verge of dying. Why you might ask? Well it was for no f*****g reason why he did, but in my guess maybe it was for is own pleasure.
3) They took her to the woods and builder her a home or a cabin and made her live there without no one to take care of her when she dies. She took care of her grand kids and now no one is going to take care of her when she dies.