Has this thread gone off topic? Here is my response to the OP.
Here are two books I recommend you read to give you insight into touring.
The Essential Touring Cyclist: A Complete Guide for the Bicycle Traveler, Second Edition</SPAN>
The Complete Book of Long-Distance Cycling: Build the Strength, Skills, and Confidence to Ride as Far as You Want
I think both books cover interesting topics. I haven’t done a tour but reading these books has given me topics to consider for my first tour.
I agree with the many suggestions to do a tour, even a two day self-support tour I’m sure would be beneficial.
As has been expressed, I think rider’s have a variety of wants/needs in a bike. As I think about “designing the ultimate touring bike”, I am struck with this thought. I think the whole thing is an academic study that doesn’t work in the field.
I think those that do tours are more independent then the average cyclist. I think they all have “tinkered” with their bike after purchase. This customizing is what gives them pride in their bike and confidence that this is the “right” bike to complete a tour on. This sense of ownership can’t be purchased in an ultimate off-the-rack bike.