I agree with Johnny - i`d keep them on 24/0 if u can. I find it helps with secondary growth etc( which is certainly helpful if ur wanting to take clones from them) and they`re certain not to flower then!!!
Don`t worry about the pistils showin either -- i`ve had plants show female sex (just as urs are) at only 4 weeks into veg.
Not too sure bout the leaf ends but i`d take a guess that it`s light burn. I wouldn`t worry bout that either unless u start to get discoulouration or spotting on the leaves or if it seems to spread.
They look totally fine 2 me - nice job :thumbsup:
Digi