You can adjust the canopy levelness by giving your babies a booster chair to the light, rather than bringing the light to the plant.

I would tranplant at two weeks...get them into a stable rooting environment. Let them have at it and give them 3 days to adjust, then at 17 days hit them with the MH and veg them til you are happy

Then one last final transplant prior to flower. Follow the fundamentals of transplant in the faq and use a the rooting hormone powder and they'll not miss but a few hours.