Might be a little late for mollases but it wont hurt. What it does is feed the microganisms in your soil, unless you have been usng high doses of synthetic nutes and then you prolly dont have any microganisms in your soil. You can use it during the entire flowering stage and up to 2 tablespoons/gal. Definitly worth it, but beware of fruit flys.
That's absolutely right. Sugars in general have some use in organic soil. For example I add C&H's pure raw washed cane sugar in a top dressing mix that includes rice flour and fresh ground coffe, azomite, bone meal and so on. The Cane sugar helps stimulate the microorganisms into action which creates a surge in populations that then die or are eaten by others things and therefore improved the soil food web cycle.
Wikipedia has some great articles.
http://en.wikipedia.org/wiki/Rhizosphere for how our plant interacts with the symbiotic.
http://en.wikipedia.org/wiki/Soil_food_web
Now the Molasses is useful but I have always read Black-Strap unsulphured is the right way to go. There are nutrients in it and no pH issues.
We all need to remember to add minerals too Azomite comes to mind
http://www.azomite.com/
So in organic soil bioactivity happens all the time and I don't flush! I'm an Organic soil guy and organic soil growing produces great tasting cannabis without flushing.
Anyway PM me if I can be of more help.