To run apache automaticly you only need to check if the file
[code:1]/etc/rc.d/init.d/httpd[/code:1] exists and make a link to it in the appropriate run level directory like this: [code:1]ln -s /etc/rc.d/init.d/httpd /etc/rc.d/rc5.d/S66httpd[/code:1]
If you list the directory rc5.d you will see more link named S... the http deamon will start after the last S... with a number less that 66 has started.
Any way, the better way to do this is by using a tool like drakeconf (capitalization is wrong) or ksysv if you have it and add the httpd script to run level 5 (you should also add it to the stop list to make it stop correctly each time you shutdown).
About the modules...the only thing I can say is: Did you installed everything?
If you did you should have a look at the configuration file [code:1]/etc/httpd/conf/httpd.conf[/code:1] (in RH) and figure out what have you changed or what is wrong.
Good luck