1. Nope!
2. Yep!
3. If done well, over time, it can be! Depends. When I was in my 20's and hadn't overly abused my liver yet, I did just fine w/o flushing.
4. Depends on which kind of intervention you do overall, your age, and symptoms. Figure on doing liver management about twice a year. Everyone needs to be "changing their filter" but your mileage may vary. ;)