TKAM Chapters 7-9

Throughout these chapters, Scout and Jem continuously discover objects placed in a hole in a tree in the school yard as if someone had left them there knowing that they would find them. One of the objects was a soap carving that strangely looked like them. However, one day they discovered that the hole had been filled in because Mr. Radley claimed that  it was dying but Atticus said that the tree was healthy. This leads me to wonder if that the real reason why the hole was filled in the hole was for this reason or if there was another reason behind it. In chapter 8, Miss Maudie's house burns down for an unknown reason. During this event, Scout unknowingly receives a blanket from who Atticus says was Boo Radley. Is Boo Radley a genuine person after all? In chapter 9, the trial is introduced to the book and Atticus is defending a black man (Tom Robinson) who is accused of raping a white women. Even if Tom is an innocent man, is there any possible way of him winning this case?