Mine has three leaves and working on it's fourth. I had it in a shallow black container that is in full sun from about 10:00am-3:00pm. The water stays pretty warm without heaters. I moved it to a half plastic barrel today that is right next to where it was. I have also given it a little piece of a Jobe Plant spike twice in three days. I am in Zone 9a and our nights are getting very warm now and the days are hot. Like you, I've had seeds sprout but die shortly after. I've gotten one to survive this time but it's doing good. If it grows and blooms, I can guarantee you that I will be sprouting more. I'm also going to try to over-winter this plant if it survives.
It will be interesting to keep this post going so we can compare notes. I did it on the mailing list with another Florida resident with the N. minuta seeds. My N. minutas are doing fairly well but no blooms yet.