1) Nearly every modern leftist protest I've ever seen has had some element of violence, as far as I can tell some people think violence is a solution to all problems, therefore whether or not this particular controversial issue incites people to violence is tangential because it is guaranteed to due to the nature of controversy itself.
2) I've already given an outline as to how statues and other forms of symbology contribute to racism and how, therefore, their removal would contribute to tolerance. It is a multifaceted, nuanced issue and I'll leave the specifics to researchers of sociology.
3) Again, the statues are forms of symbolism, of a kind which represents issues stemming from the aftermath of the civil war and not directly from the causes of the civil war.
4) I've given you my answer, I grant that for some people they are statues of great great great grandpop and for some other people they are items of sexual fetish.