Bring on a guest and just going at it with no research just doesnt cut it, as we know. Dan researches what questions he wants for the guests, at least the main questions and goes from there. Otherwise, it can go haywire and be boring, especially if you are limited by time constraints and more. As one who does interviews, it can be difficult just to think of the right questions without consulting your notes, and more.
Just try it with someone for about 20 minutes, it is much more dofficult than you think.
As for the typing you sometimes hear, it is probably because Dan and Bob IM each other, especially since they are in different cities, and that is the best way to get notes or comments or discussions on what will happen next, etc. Or else they are reading Getbig at the same time
Dead air happens, especially with technical problems, unexpected situations, etc.
I had dinner with Dan at the Colorado Pro one evening, and Dan is one of the pioneers in the bodybuilding radio concept, having the courage to come out with a radio show and being one of the firsts that many people now listen too. And he is a cool person also - I got a hat and shirt from him