Let me preface by saying that I've had many similar thoughts.
I don't plan to compete again. When I did so in 2003, I was proving something to myself - that I could put 100% into it and succeed - unlike two half-arsed "efforts" many years ago. Having siad that, yes, it was rewarding because I felt good about the half-year journey, pitting my education and effort against others (some of whom chose a different route to the stage)... and yes, it was educational, giving me a first-person perspective of what it's like to be in a "national qualifier" event.
Yes; I sure do.
My plan involved a full 5+ months. Surprisingly, my family didn't have to deal with crankiness. By cutting carbs in the evening and religiously doing pre-breakfast "cardio", results cam without obsessiveness until the final month or so. Even then, I knew that my diet and extra gym time was a personal choice and not something to belly-ache about to loved ones.
Tough one. Hmm. Take your time and do it right. Fat loss without muscle wasting takes time and a well-conceived plan, counting backwards from a competition date. I even included a mass building phase prior to (and during) the early stages of kcal reduction. Each month has its purpose. I'd also say that absolute commitment is key; as Tom Platz says, it can be an almost religious experience when one's heart and soul are into it. I valued it beciase I know it wasn't something I would do repeatedly.