I have a leopard for 5 months now so I can only give you information I have read about them. It is so funny that you said that about the grasses because I have posted so many times "PLEASE TELL ME SOMETHING THAT I CAN FEED MY LEOPARD THAT I CAN BUY IN A LOCAL GROCERY STORE" After many months of still not knowing "exactly" what is the best thing for them-I found out that you can not go wrong with a variety diet. I feed my leopard Spring Mix letture (local grocery store) small tomatoes, timothy hay, and some dandelions. He also have alfalfa (sp?) in his cage that I have caught him munching on every once in awhile.
The temperatures for mine-and if anyone disagrees please voice your opinion it only helps me too~On one side I have a basking light with temperatures around 90 and on the other side I keep his hide (which is a must have-he loves it) and it stays around 75. I have a big uvb light on the whole cage.
I soak him every other day in luke warm water for about 10 minutes. He likes to drink from it and then poop in it!
As far as "hard to keep" I really can't help you-I have heard that they are a little harder to keep, but I think next to the Indian Star-they are the most beautiful. He/She is super friendly and eats from my hand. It is so cute and I haven't had any problems.
I hope I was at least a little bit of help! Good Luck!