I've had a Green Clown Goby for two days now, and he's been eating everything. The hiding spot he chose isn't nearly as out in the open as your's picked, so I have to look for him a bit.
Anyways, he eat's New Life Spectrum Marine Formula, the tiny pellet size, and my clown fish and the goby both eat cyclopeeze too. I dumped a full bottle of trigger pods ($24!!) into the tank hoping they wouldn't all get eaten and would reproduce, but while the pods were settling my clown fish was going crazy on them, along with the goby and peppermint shrimp. The goby darts out of his hiding spot, grabs the food, and darts back in. I'm hoping he becomes more comfortable and decides he can sit out in the open soon.
I have yet to get out the flashlight, but I have a suspicion that the goby moves around a lot more at night. Maybe you could check your tank at night to see what's going on?
And a question about those sexy shrimp. I saw them at a LFS today for 18 each, would you say that's a fair price for something so small? And do you think they would get eaten by a peppermint shrimp, (1.5") goby or the clown which is about 2"?