Glad it's thriving! In most of my cases, the ones stunted early go on to do just fine, sometimes just produce a lil less. But again, these can be very interesting plants in that, in some freaky cases, early hardships can make the plant produce more. Some growers are really good at employing stress tactics to get their plants to make more, but that's a delicate line to walk and a whole 'nother level.
Well, the lifespans aren't really as set-in-stone or as hardcoded as that. The time they begin flowering is pretty well hard coded genetically, but after that, environment and a few other things can stretch or shrink the time to finish. It might go to 12 weeks from 10, it's hard to say.
After they complete the last growth spurt (aka final stretch) is when you'll get a better feel for when they'll finish... but that takes some experience to get a feel for. These are tough plants to predict haha, part of what makes them so fun!
Anyway these are all good valid questions we've all had.
I think you're doing good, keep growin and getting experience and things like this become more understandable.