Is it ok to just use a toner and moisturizer everyday til the next exfoliation day...when exfoliating once a week?

No, you really should wash your face with your 3-step-system. Exfoliation isn't a long lasting face cleanser, it helps shed bumps, blackheads, and dead skin off your face. You will have to exfoliate less if you cleanse your face to get rid of dirt and germs before they turn into blackheads and acne.