Sucrose can be regulated by your body with Sucrase, whereas HFCS cannot. Maybe that's part of the reason why so many Americans are overweight? Hard to escape HFCS in the average diet. Reference:
http://en.wikipedia.org/wiki/High-fructose_corn_syrup#Cane_a...
Yeah, but if you consume enough sucrose and you don't cleave it, you'll get the equivalent of lactose intolerance (lactose is a disaccharide of glucose and galactose instead of fructose).
Given that sucrose is half glucose, half sucrose, and that none of it can enter your system without the molecule getting cleaved, yes. And sucrose is not a new item in the British diet (think of the Caribbean plantations) and I've read it was at least for a period (but not one in which anyone was paying attention to this sort of public health) an important part of the diet for many poor people.