I wouldn't go with a 24 hour light cycle, even for vegative growth. My understanding is you should try to mimic the sun as much as possible so I'd put um under 18 hours light/6 hours dark. I would also just use the MH lamp for the enitre grow. Florescents can be used but I still believe that your plants will be kinda spidily and weak. As for male and female characteristics the females are usually shorter and flower later than males. the males have little sacs of pollen and the females have two white hairs in the shape of a V for their preflowers. Anyways good luck. And you should read http://www.sharprubberduck.com if you haven't already.