Best Damn Workout, The Month After?

Hi CT, regards from Argentina, and thanks for sharing your knowledge with all of us.
I´ve been doing the Best Damn Workout for almost 3 months with impresive results. Now I want to make a one-month definition phase to get rid of 2 kgs.
Earlier, in other definition phases, I had the sensation that I was loosing as much muscle as fat, so I want to be more cautious this time. My guidelines will be:

  1. Caloric Restriction: 15-20% of my mantainance level
  2. Carbs mostly during peri-workout
  3. Full body training, four days a week, with one basic movement each for strenght (5x5) And the rest mostly supersets and circuits with barbells and dumbbells.
  4. 40-60 minutes walking daily

I would appreciate a lot your opinion or suggestions. Besides this, my main doubts are:
a) How much cardio should I add? I normally don´t do a lot.
b) How to eat in non-training days, since once you recommended to consider them like “growth days”. I normally consider them with even more caloric restriction to compensate a weekly re-feed

Thanks a lot!!!