Correct. But you'll never keep it in flower until then. It will finish long before that. Most commercially available strains take around 8 weeks of flowering time. Purer sativa strains will take 12+ weeks.
That's your call. Ahh the joy of choices. Haha.
Personally I would just put them all outside once your past your last frost. Males typically show before females, the chances of the oddball being male are low. If it is just cut it down. It's not like an indoor grow where you end up wasting light your paying for.
