Just feed NLS cichlid formula and spirulina flake. The gobies and plecos will love the spirulina and also eat algae in the aquarium, im assuming you have a healthy well established tank, but also nibble on the NLS, and all the other fish will eat the NLS and get the protein they need. The only problem with too much protein for you gobie is the development of bloat.
*** been feeding this combo for about 2 years and only very occasionally add in another food and have had great success.
Gobies do great on NLS alone. That's all mine have known since very small when I grew them out on NLS grow, the one with the high protein. The protein in it doesn't cause bloat. Just find a good quality food and they'll all be fine. I can't answer the question about the mysis shrimp though.