In regards to your summary paragraphs,
Therefore i think, having a "nice", lean, cleaned-up config file is better than a single large one that tries to fit all purposes and legends.
Absolutely. In that way, configuration stays accessable.
Actually, i think the main problem is that many people "love" their old config files and do not dare to change anything, because they think that every change might endanger the stability of the system. In my experience this is rather an alarm signal. When people are not daring the touch anything in a code it is a good indicator that this piece of code is overly complicated and should be overworked.
Yes. In my own case, I would always use the most current, not daring to try my old config on the new server version. Your indication is still the same.
Perhaps people would be less nervous if they saw that while aolserver/naviserv has its own config params, and that it is the loading of most (?) modules that adds additional params which would then be recognized in the config file, if they could see it's not just a monolithic, incomprehensible and uncontrollable mess (the perception of which we inherit from arsDigita days), but a fairly logical structure, they might be less nervous and more bold and confidently able to know and set their own params.