It is probably a bit too late, but anyway..
Black balance is setting for blacks for the time being (generally you would want it neutral as any stylization is usually done in post).
Flare balance is just for shot when camera is directed into a strong source of light, which could cause shift in colour and raising blacks (ghosty image). You can reduce this effect with this setting, sadly there is very little material about this topic. If you have any please let me know as I am playing around with this setting right now.