Hey m8, nice plants...i gonna try to answer a few Q's, but i think you should maybe wait for someone else too...

I think after the switch to 12/12 you will need to remove the males, it will take max. 1-2 week to find them all...

About the bloom fert...you should get some organic bloom fert. most people here use foxfarm nutes - Tigerbloom i think, i use the BioCanna products, i heard BioBizz nutes are also good....

Don't know about that 48 hours of darkness tho...i think you should just set the timer to 12/12...

After the switch feed the plants whit veg fert(fish emulsion is good i think) for 1-2 weeks, then later you should use veg+bloom nutes together for a few weeks, and in the final few week use the bloom nutes only....