I too was having problems with asterisk and freePBX during installation, but with a later snapshot (24164) I didn't have any problems.
However, I still was not able to register the line, and like you, asterisk.conf was missing. Somebody on IRC gave me this file, I plonked it in, and the line registered. If you want me to send you this file, let me know.
I've no idea if this is related, but still none of my extensions have registered with freePBX. The internal intercom doesn't even work - does this use freePX by any chance? Not sure where to go from here, I really don't want to reinstall if it can be avoided.