Hi,
 The install when run through yum eventual calls pkicreate.  For a bit
of
 usage enter pkicreate -h  
I use pkicreate to create RA too. But it didn't work too. The same error 
- httpd.xml missing and Internal Error on RA configure page.
 There is also a pkisilent which can be used to configure a subsystem
 that has been installed. I.e. it replaces the web based wizard.  
I should try but:
-bash-4.0# yum search pkisilent
Warning: No matches found for: pkisilent
No Matches found
-bash-4.0#
BR,
Rafal Kaminski