There are many mixed race couples here, majority though are military. There are sex offenders in both counties, You can check out these websites.
Augusta/Richmond County
Sheriff's Office - Offender List
Columbia County
Columbia County : Sex Offenders
Just like any city Augusta has its issues. Unfortunately some are pretty dumb and petty. But hopefully it will get better in my lifetime.
Grovetown area is rapidly growing LOTS and LOTS of new construction and neighborhoods going up. And its predominately military.
Here you can check out local real estate in the MLS
Main
Good luck! and welcome to Augusta.