I don't think history should be "censored" because it happens to be reprehensible or because reprehensible people can exploit it. If not counter-productive, I'm not even sure such censorship will be very beneficial or effective.
I think history, regardless of how reprehensible it might be, should be accurately and "objectively" represented and stand as a truthful (and cautionary) record of the past. I mean, c'mon, let's not be pussies here.
If and when slavery is glorified and/or the Confederates are portrayed as victorious heroes, then that should change, not because such representation is "mean" but because it's inaccurate.
As for the naming commemorations, I personally wouldn't mind changing some of those names, but that should be up to the locals and done in a lawful manner. While we're at it, I'd like to see the same done with J. Edgar Hoover's name, and we could start with that FBI building, but I happen to think that the FBI's existence is unconstitutional, so meh.