You also need to decide if you really want to limit yourself to CSV's. The mod_xml_cdr module is extremely powerful and maybe lend itself to the whole "CDR daemon" concept. You could have your daemon listen for POSTs from xml_cdr or you could just have it scoop up the .xml files from freeswitch/log/xml-cdr/ and process them. (Either way would work but if you have it use the HTTP POST method you could more easily build a distributed model.)

I'm partial to mod_xm_cdr because it gives a very complete picture of what happened on the call.
-MC