Quote - Have there ever been fully realistic (i.e. directly derived from full body scans) characters sold in the marketplace here or elsewhere for Poser/Daz?

Well, there was Dina.  She was supposedly built from scans of a real person.  A bit top-heavy, but her height and leg proportions were more realistic than Vicky (as I recall, she was about 5'-7", compared to Vicky's nearly 6'). 

And if more realistic proportions were what people wanted, they would be characters/morph packs to achieve it.  There are vendor add-ons to make the already leggy Vicky longer-legged...but not shorter.  There are some morphs to make Vicky's boobs smaller, but far more to make them bigger.  More realistic facial proportions are achievable, and there are some in the marketplace...but they are few compared to the big-eyed, fat-lipped, hot-selling dolls.