The only pseudochromas I would consider with seahorses would be the Orchid Dottyback (Pseudochromis fridmani).
I guess you could try your bicolor but be prepared to remove the fish on short notice if it acts up. It will probably be a bit of a project most likely requiring removal of most of the aquascaping in order to catch the fish. It may not be worth it.
Your little Clown gobie however is a perfectly suitable tankmate. I would have no worries about that fish at all.