Hey man, nice little grow.
not geting much help r u ..... anyways about ur pots, i think 7 lts will be just fine, don't repot to many times.
also i think now is the right time for 12/12. The girls (hopefully) will pobably end up about 3 time the size now! and alot bushier...
What soil and nutes are u using? and are temps under control with door closed and hps runnin?
what are the dimention of ur closet?