You miss a large point of the story that is clearly detailed in the book. This was a small Southern town where people knew and protected each other's children. While Bob Ewell did threaten Atticus Finch, the concept of harming a child in that society was unthinkable, even for a low life like Ewell. The theme of small town innocence is much more pronounced in Truman Capote's "In Cold Blood." In fact, the work, which Harper Lee assisted with research, is still considered a landmark piece of non-fiction for its use of fictional style and, for that time, brutally graphic description of the murder of four people.
"To Kill A Mockingbird" is based on a trial Harper Lee's father worked on during her childhood, with obvious fictional components. While the Civil Rights message is clearly evident, the theme that wasn't explored was how much Southern businesses suffered because of the overt racism throughout the region. It's true racism existed in the north (and still does), it was in covert form, something Martin Luther King, Jr. struggled to understand and work through.
As for killing a rapid dog, at that time in history people were allowed to kill rapid animals on their properties due to the fact county and city police forces were thinly staffed, there were virtually no veterinarians in small towns and first responder services were non-existent. Hell, there were limited medical staff of any kind in towns like that and if they were practicing they were overwhelmed and didn't have time to assist with animal control.
Lastly, many groups – conservative and liberal – consider Atticus Finch as the fictional hero of the 20th Century.
By the way, the word is "Character."
I like your comments, they made me think and reconsider.....though your last line was a bit petty, wouldn't you agree.