I see a lot of valid points on these but I have to wonder if Chrysler did it on the big cars, could it just be so they wear less and last longer.

Seems like if you are selling an expensive luxury vehicle you don't' want them to wear out too soon.

As for the small vette tie rods maybe they were looking at reducing the weight to get better suspension reaction. They obviously did the math so they wouldn't break too easy.

The only real wear spot would be the ball and socket, are those any different in size compared to the smaller diameter ones?

No. Same ball and socket.

The diameter of the solid male threaded part of the 11/16" tie rod is thicker. But IMHO the hollow rolled adjuster with open slot is weaker than the Tie Rods.

True, I imagine the best bang for your buck would be a solid adjuster rather than up-sizing to 11/16"

The adjusters in my 51 Plymouth are a solid tube, not rolled, from the factory.