I've "cut" once in nearly five years of lifting(3 serious) I started really chunky and lost it slowly while lifting.Once I got to my target weight I started putting muscle back on. I cut down to around 220ish last summer and up to Novemeber and was below 10% BF. Other than that I'm back to gaining size and loving every bite.
I would definitely say no more than that. I think that probably an extended bulk is the most effective means of optimally putting on mass if that's the route you want to take. Personally, I like to alternate a few months bulking with a few months leaning out and keep repeating. It depends how much fat you are willing to carry on your frame
I've never cut in the 11 years of training. I won't until I get to my goal weight and size. I think more people should do the same, because you're wasting your time if you continually do so. All you need to do is control your cals so that you don't put on too much extra weight. Cutting is for competiton or wanna-be beach bods.
No less than two months, if not more. Any time in the past that I have dropped weight soon after reaching a new "higher set point", I will lose more of what was gained in terms of muscle mass. Muscle uses calories to en extent that your body won't find efficient unless you hold a certain weight long enough for that to become "normal" for you.