If the temperature variable is less than 15 degrees F (hotter or colder) in either direction (from indoor to outdoor or vice-versa), the plant will not go into shock and you can move them back and forth with ease.
you should be doin 18/6 from seed or clone. 24/0 or 20/4 is more for auto flowers..just my personal opinion.
It wont stress them to move from one veg to another veg, as long as u only do it like once or twice.