you dont have too but I would allow at least 8 weeks for flowering, may take 10 or more. all strains are different. so I would say vegg until end of august.
Ive never moved from out to in but it shouldnt have any dramatic effect on ur yield I wouldnt think. You can force if you want to. One thing Ive learned is that every farmer has their own style or methods of growing so you never get the same answers.