It is normal of leaves to yellow in the last stages of flowering NOT halfway through it. Feed your plant, man, or else you will be disappointed in the scrawny buds that develop.

It is not nessicary, I belive, too not have to give your plant nutes during flowering, nutes just increase the speed and quality, and quantity etc.
I guess your statement is true but if you don't care about the speed, quality, and quantity then why grow in the first place, just buy it and save yourself some money.