its simple, get a goal and stick too it, if you ant to bulk, bulk, keep gradually increasing your food intake, eat the right foods and adjust your training to match your diet and goal, if you stop training, get lazy etc etc yes your body will shrink back down if you stop eating, steroids just help put the icing on the cake, they are a toll to help and some drugs help in different ways.

food is the most anabolic substance known to man, keep a positive nitrogen balance and grow, tear those fibres down and eat big to recover big/quick. good luck.

It would still be effective off cycle however like everything else involving muscle mass, when on steroids the results will be more dramatic lol.

I doubt you would plateau on cyclic bulking, its the whole reason for it. The constant changing of kcal. If you hit a rut in the road try changing up training

Hard to say without knowing you peronaly but yes eat a lot of clean food this is how you grow. It's not the drugs or the dosages we grow from real wholesome foods not pizza and cheese burgers. Now don't get me wrong some guys need to throw in a burgers here and there but this is on a individualistic basses.