Answer:
Pap is extremely rude to Huck and beats him. There is nothing that he can do. Huck thinks he needs him in his life but he doesn't. After Huck finds out that his father has been dead for some time now, he realizes he doesn't need Pap. He realizes that Jim is more of a father than Pap ever was.
Jim is just plain stupid and always getting himself in trouble. However, he gets himself in big trouble when he gets sold for $40. Luckily, Tom and Huck create a plan to get him free. Even though they go through so much trouble to set him free, the do get him free.
Aunt Sally sends numerous letters to Miss Watson about Jim, but thankfully Tom intercepts these. If Miss Watson knew about Huck, Tom, and Jim they would be in a lot of trouble, and Jim would be sent directly back to Miss Watson. Even though they wanted him free, they wanted him to actually be FREE and not go back to Miss Watson.