My only ASCII app on an 06 was transmit only, with a remote system collecting the transmissions which were status and data of a test sequence, parsing them, and entering records in a database.
I found it easiest to use the "PRINT" command and just assemble the constant and dynamic portions of the message on the fly. As far as flow control, just jumper RTS and CTS together and go without.
If you're doing control and/or monitoring of the remote ASCII device, you'll probably have to deal with return strings as well, parsing them, looking at the contents, and possibly taking some action based on what's in there, so there will be some additional work on your part to do that.