Is there a way to use SSL with the standalone APEX Listener by using Apache as a front? Has anyone done this and can share instructions, please?
It is better to deploy ApexListener in a J2EE container as has been discussed often on this forum.
The answer really depends on what all you intent to do with the Digital Certificates. If the purpose is only to create a secured transport and simple mutual authentication then you could deploy the Server/root DC on Apache / OHS.