We can always ask the experts for some guidance but some things require common sense. As to the amount of acceptable sugar intake one needs, it isn't recommeded to take too much. Not that it is the cause of diabetes but it can worsen the existing situation.
Personally, minimizing or cutting out sugar until BGL is normalized is a better approach but one can opt for the natural sugar from plants like Agave.
As in all things, there needs to be a balance of the essentials such as vitamins, mineral, and etc. So, it is with insulin. Most look at improper dieting i.e. eating too much sugar or too much carb intake as a problem but in fact the problem is in the correct amount of insulin to reduce excess blood glucose level.