You said..."What do they look like? Are they hard or soft?"...when first laid they are about the size of one of those fancy flavored jelly beans if they are infertile. Fertile eggs look white and "solid" but infertile ones have a more yellowish look to them. Generally they will mold and look bad in a couple of weeks.
Eggs that die during the incubation process will mold and eventually shrivel up generally.
You said..."I ask because batch of panther eggs I have has turned brown and a little moldy. I have moved them from one container to a all new one(I rubbed the mold off to. They still look good but I'm not sure. any tips would be great!"...can you post a picture of them? I never throw away an egg until I am certain that its bad.
You said..."I also had a female veiled release about 12 eggs on the bottom of her cage. They were all soft and slimey? I don't understand why she did this because shes still flashing gravid colors?"...you didn't say if she has been mated or not. Did you provide a place for her to dig to lay her eggs before this happened? Sometimes when a female is mated at the "wrong time" in her cycle she will lay some infertile eggs and then go on to lay a fertile clutch. This could account for her coloration too.