Question
sugar cure?  JUST HOW MUCH AND HOW OFTEN, WHEN? AND HOW DO YOU   APPLY IT ? HOW LONG DOES IT TAKE TO CURTAIL THE PROBLEM.

Answer
There is a large population out there that believes that if you improve the soil alone, all the other problems will be solved. There is some evidence that sugar or molasses applied to the soil will improve it. It is therefore reasonable to conclude that applying sugar to the soil will solve a broad leaf weed problem in a grass lawn.
It is never as 'cut and dried' as that. The soil is a  factor, an important factor, but not the ONLY factor. Attempts to improve the soil are necessarily long term.
There is no sure fix in a short time. I hope that you will understand why I cannot answer the five questions you have posed.