No, I'm sorry, I beg to differ. Think of flowering as autumn for your plant, when the leaves change. The plant is using up the available N in the leaves as it flowers, and if you've fed it right during veg, it should have plenty to last it until harvest time. Yes, you could add a little more if you think it won't make it without using up its stores, but really, for flowering, your plant needs higher P, or phosphorus, as it is using that for bud building. N is only really essential in vegetative stage. However, even bloom nutes usually provide some N, and this is plenty. Different nutrients for different times in a plant's life, kind of like how dietary needs change with age in humans. As for flushing, some folks never do it, it's more of a matter of taste, if I'm not mistaken. Some folks swear if you don't flush the last two weeks, the taste is compromised. I personally believe in flushing because I want a clean smoke, and I think it also kinda lets the plant "know" that time is almost up, thereby making it increase resin production. I'm not an expert, however, and I could be wrong in that. But I do know yellowing is normal during flower, and natural....like I said, it's autumn for your plant. I've also heard introducing extra N in flower is going to make your yield smaller, as P is what is needed for good bud production.