In response to your question regarding Sugar content:
1 glass of orange juice usually has around 24 grams of sugar. If you do the lemonade by the book and use 2 tablespoons you have about 26 grams of sugar. So it is very similar.
I just checked regarding fructose in fruit juice and what type of Sugar is in Maple Syrup. It is 90 - 96% sucrose and up to 4% glucose. So it is a different type of Sugar and is most likely digested differently.