Congratulations, very well put.
I responded to opcdba in another thread before I read this one. As you say, if you are the average car buyer, the manual recommendations are fine and will certainly get the car down the road for several years until you get tired of it. If, however, you want a long life, you exceed those recommendations.
I'm not sure if this is opcdba's first MB or what. With many other makes, mostly American he is right, there is nothing left of the rest of the car to put an engine into when the time comes. An MB if taken care of can hold up for several engine lives in many cases.
MB nor any other car manufacturer is truly anxious to tell you how to make your car last for twenty years, they would certainly go out of business if they did. They have let the general public believe that a car is good for 80 or 100 thousand miles.
There is one other area where I feel that the engineers are not allowed to do what they would like in some cases. That is see that everything is accessible for the poor folks that have to apply the wrenches to them. Some manufacturers are much worse than others. Again, you can guess where the manufacturers with the most difficult cars to work on are located.
Change oil hot and change oil often,