I have an idea but i'm not sure it's possible.. to duplicate the appearance.dbf and call it appearanceAWAY.dbf (this file will have all players wear black socks) and somehow make the game use the original appearance.dbf for home kits and use the appearanceAWAY.dbf for away kits, this will also solve the home/away sleeves problem.
Again, I don't know if it's really possible but that's the idea which crossed my mind.
make a bat file that will rename your apperanceaway.dbf to appearance.dbf and rename the original to appareance.dbfbackup. and create a shorcut of it in the desktop. then just click it before you play your away game.