Just because you use Gentran doesn't mean that Sterling is necessarily your one and only VAN. In our case we use Gentran as our translation software, but use several methods for getting the edi data to/from our trading partners. (Vans, ftp, as2).
Some VANs will do delimter conversion for you, but that may be only for incoming data so that all data from them uses the same delimiter/separators. Sterling can do this and probably most of the other VANS if you ask. I don't think that data from you to you TP can be converted by the VAN, so whatever delimeters you use thats what they will get (unless they use conversion on their receiving end).
I have found that non-printable chars are a pain! Most of our TP will accept alternates and you should check with your TP to see if they will accept a alternate (printable) delimeter ("~" or "^" are ones we've used). In particular is seems the hex 0d and 0a are problems because the crlf is used by so many things for record termination. Even some methods of transmission use crlf for block records termination, so if you used it as a terminator it would be very messy.
I don't think I've run into a TP that ever had problems with the separators we normally use (*,>,~ for element, subsep and terminator).
As a additional step, maybe after translation you could run the output edi file through a process that replaces your gentran terminator with a cr. I don't know what o/s your running on but unix I've used a 'tr' command to do something similar to this.
LEE