All of your questions have different answers. It depends on age and condition they're in.
I have both adults and a juvinile. I care for them slightly different.
For adults:
I keep my male in a 24X24X36, and the female in a 16X16X30. I feed them every other day and sometimes every three days. I try to keep the humidity around 75%, but I don't allow it to get below 50%. I supplement them every two weeks with one or two crickets lightly supplemented with calcium WITHOUT D3. I keep their temps around 75, and it drops to about 69 or 70 at night.
For Juvis:
I keep my juvi male in a 18X18X24 Exo-Terra. I keep his temps around 73, and make sure the humidity stays about 85% or higher. I don't allow it to get lower than 75%. I feed him about everyday. I cup feed him, so I just look in there to see how many crickets he has in there. I supplement him the same as the adults, sometimes a little more, just because he's growing. One interesting thing that I found, temps over 75, you need portions of the cage that are cooler, and more humid. The little ones can get overheated fairly quickly, and making sure they can cool off is the most important thing.
LPR08