Flower, the problem that I see with reseeding your sandbed with the goby present, is that as soon as you add some active sand to the sandbed - the goby is going to swoop in and immediately begin sifting that sand looking for the microfauna that it naturally subsists on. So unless you are going to add a very large volume of LS to the aquarium at the same time, I don't know that seeding without removing the goby will be successful. You might try removing the goby for a period of time and then reseed, than at a later date after the sandbed reestablishes try adding the goby back in. However, if it then strips your sandbed again, you are right back to square one.
On a happy side note, if you decide to remove the goby, it should be realitively easy to trap and remove - use a simple bottle trap and place a few spoonfuls of LS from your fuge to the ******** of the bottle and within a realitively short time, the goby will be trapped in the bottle trap happily consuming the LS.
Once you get your sandbed restablished, so long as you are not overfeeding, you should be ok in the short term. I'm not much of a fish person, so can't help you much with the stocking - for what its worth, here's my thoughts on the others; In the long term, the hippo will probably have to go, and they get quite large. I don't anything about the kole tang. The dottyback should be fine, but watch the blenny, I've had them start to starve once the algae ran out (they don't convert well to feedings). The clowns are fin as is the lemonpeel, but watch the lemonpeel as I've seen them eat zoanthids.
Don't know how much that helps you, but hopefully some.
