I don't think the person you presented looks like the average believer. It might be useful to actually engage with real world people.
I don't think Theo in the dialogues is meant to be like an average believer; nor is Art meant to be like an average nonbeliever. Rather, the whole debate is there mostly as a hook on which to hang various lessons in how to address difficult and contentious topics. A real debater who spoke like Art would probably sound annoyingly pedantic and pompous (with the constant refrain of "now I am going to apply such-and-such a technique"), but of course those bits are really addressed to the reader much more than they are to Theo.
Inspired by the call to go forth and make rationality reign...
I've started a blog at http://www.bettertoknow.wordpress.com
It teaches discussion/debate techniques by showing them at work in a dialogue about the existence of God.
I don't expect theists to read it much, but atheists will be able to discuss theology (and everything else) more effectively with theists (and everyone else) after reading it.
With that in mind, I'd much appreciate critique of the plan and execution.
Am I thinking clearly? Am I expressing the ideas well? Am I taking too long to say things, using too great inferential distances, or strawmanning?
And on another level, am I using the wrong website to blog? Are my posts too long? Are they missing some important element? Should I be doing anything differently?