As you know, your tank isn't cycled yet. You must monitor the ammonia and nitites. I do a water change weekly. You should do the same, but may have to do more if the ammonia and/or nitites rise too high.
Make sure your gravel isn't too deep. The UGF need about 2 inches of depth to be effective.In a 30 hex, you have less area for the bacteria to grow, then a standard 30.I suggest a mechanical filter in addition to the UGF. The UGF is really for Biological. You should get a simple filter like an aquaclear or whisper to help get the debris out of the water.
Make sure you limit your feeding. Dont let any flakes hit the gravel, the kissers and Blues are *good eaters, so I dont see this being a problem.If they do..your feeding too much. Once a day and just so everyone gets a couple flakes is fine.
I would defenitly not add another fish until you are finished cycling.When ammonia and nitites are 0 and you have nitrates.
Make sure you vaccuum half the gravel to keep it from getting clogged.
Add the stresscoat to the water you are adding before you put it in the tank when you do a water change.
I found gourmis to stay in one spot near the surface, so he may not be in trouble. If it is an oxegen problem, the airstone should resolve it.
The water can goto 80f and not be a pronlem.Even a tad higher is ok.
Remeber the kissers can get big, and the blue gourmis can get 5 inches...so you dont have a lot of room left for more fish. I suggest Ottos after you cycle to eat any algae.
HTH
