Plated Lizards do shed just a few scales at a time. Overall it can take a long time for them to go through a complete shed. As for taming, I couldn't tell you. I don't handle mine and they all tend to be a bit skittish although they will eat superworms and some other foods from my fingers. Search around on the net. There are at least a couple other Plated keepers out there who have experience with taming theirs. I will tell you though that in my experience the Gerrhosaurus validus [which I believe you said you had], tend to be far more skittish and less handle-able than the Gerrhosaurus major. I've also had experience with Gerrhosaurus nigrolineatus and they were quite skittish too.
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Matt Campbell
Animal Keeper, Small Mammal/Reptile House
Lincoln Park Zoo Chicago, Illinois

Assistant Curator
Wildlife Discovery Center at Elawa Farm
Lake Forest, Illinois