Eu resolvi isso ...
%post --log=/root/ks-post.log
exec < /dev/tty6 > /dev/tty6 2> /dev/tty6
chvt 6
#mount the cd (ISO in my case) to copy files from it
#since this is chrooted environment
mount /dev/cdrom /mnt
cp -rf /mnt/JOTC/src/jotc/ /opt/
cp -f /mnt/JOTC/src/service /etc/init.d/jotc
#starting a service is dead simple
chkconfig iptables on
service iptables start
#opening a port is a little trickier
#this line adds a rule right before the word 'COMMIT' in iptables config
sed -i "/COMMIT/ { N; s/COMMIT\n/-A INPUT -p tcp -m tcp --dport 8888 -j ACCEPT\n&/ }" /etc/sysconfig/iptables
iptables-save > /etc/sysconfig/iptables
service iptables restart
Espero que alguém se beneficie disso. Demorei 3 dias para descobrir tudo :) (meu arquivo de kickstart tem ~ 50 linhas a mais).