if heat is an issue the cfl's would be best. if not there are dual spectrum bulbs that are a hps/mh hybrid. you get best of both!!!
i think it would handle 5 but that would be about it unless you can lollipoip or sog it!!
not even close. at least a couple more weeks imo. 12/12 isn't really when you want to consider counting for flowering. it really starts when the pistils showed.