What is the best way to use Obagi Nu-Derm with Hydroquinone kit?

Hi, I have been using the Obagi Nu Derm with hydroquinone for 2 weeks with Obagi Retinol 1.0% and my face is no longer peeling. Just a little red. I am thinking of switching to Obagi Tret instead. Is this no peeling, a sign that the kit doesn't work anymore on my skin? Is it safe to use Obagi nuderm with hydroquinone full system to 6 - 12 months? Or maybe lifetime? If not, how long should I use it? How should I incorporate Obagi Vit C and Sunfader.