Average I would say at around 6ft, from germination to harvest, well you run (in Aus anyway) from Father's Day to Mother's Day.
6 feet if you know what you're doing, 3 or 4 if you're a noob. When flowering starts depends on the light cycle, it's based on time of the year mostly not time from seed. Although you can get preflowers around a month into veg.
Yes, that you have a hungry plant ready to load up with fuck loads of insane poison to fuck with your mind ! Oh, and don't pluck the fan leaves, unless of course you want to slow growth down during veg or fuck your plant completely if it is in flower.......