First off the last pic looks great to be just under a month. Definitely have a very indica look but my guess is there is some sativa in there to. As far as the auto flowering thing, if you figure something out let me know because I want to try it with a couple plants. All I can say is if you use a box or whatever you use to decrease the light hours.. make sure the plant still gets air and can breath. As far as your NPK values I think you'll be good for a while.. as they get bigger and we head towards June you might want to supplement it with something else at low strength. No need to feed them anything if the plant isn't showing deficiency or abnormally stunted growth. Best way to tell what your plants need is to just observe them and they'll let you know. Good growing.. hope we all have a great season