Nitrogen should be STRONGLY decreased at the start of flower, down to 50% or less the number from veg, and after the stretch period, if you are still using quite a bit, get it down even LOWER. N makes leafy green growth, when you want flowers instead!

2 weeks before harvest, you should actually not be using much in the way of ferts at all, since that is your flush time. Molasses is fine though- you can use it until the end. All you need is about a tablespoon per gallon of water. Too much CAN cause problems, since there are other nutrients in it, so go nice and easy. A little goes a long way.

Along with your sugar supplement, if you want to get fancy, you can use a carb synthesizer like Sweet or TopMax at a low dosage to help the plant USE the sugars. Also, remember to use your bloom fert products, which will give the plant all the P, K and micros it needs to make sugars and resins, and stay healthy.