The Confederate flag is a poor choice of symbol to represent the cultural history of the Antebellum South if that's what you're after. While many will argue that the cultural history of the Antebellum South is inseparable from slavery and therefore should not be celebrated, having grown up in the South, I know this is an unacceptable idea to many Southerners. In an attempt to find an acceptable middle ground, I think it is important that there is some consideration given to the fact that the Confederate Army was literally an army that fought to keep slavery intact, and that the symbol of such isn't going to be well received by the modern-day descendants of slavery in particular. I think historical flags from the pre-1860's seccession era would be generally better received.
Having grown up in the South but now living in New England for about six years now, I've come to realize just how ingrained racism is in the South and how much of a negative force it truly is. I've tried to explain this to people who have lived their entire lives in New England and the only way I can think to describe it to them is that the issue of race is literally unavoidable in the South as it is today. You can be a white or black person from New England who has no ill feelings towards the opposite race, but if you move to the South, you will literally have people hating you for the color of your skin. You will start to avoid certain areas and certain situations based purely on the racial divide in the area. It's a really toxic thing that needs a major effort put towards resolution. Changing the flag is such a minor thing that could actually make a large impact in this area as it is majorly symbolic in terms of putting the past in the past.
