Opinions on my tank

[AnimalMother]

I have a 55 gallon fw tank. I have had it for about 9 years. I was the idiot who just decided I wanted a tank and set it up with little research so it was rocky for about 6-12 months. Ever since it has been very healthy and the fish only seem to die of old age. For the past couple years I have not added anything because I had an iridescent shark (didn't know how big they got) that was HUGE- about 12 inches. He got to the point where he was basically a renegade recking ball in the tank. He even jumped out one time and my husky pounced him- he still lived. I finally re homed him so he now has much more space 200+ gallons although I don't believe this fish should be so readily available in pet stores due to size requirements. Since he is gone my tank looked a bit empty so after finally being able to make it pretty again and keep the deco straight added a few fish. Here is what currently resides. A common pleco (about 10 inches long) a weather loach about 7 inches, a golden gourami about 5 inches, 2 kissers 1 about 5 inches one (new) about 3 inches, a rainbow shark (new) about 2-3 inches, and a red spotted gold severum (new) about 3 inches. I had a rsg severum from my original set up that passed about a year and a half ago and so I wanted another- I love them! Any advice or opinions on my tank- are single fish of a species happy? The only one that seems to be a bit of a bully is the larger kisser (of course) but he isn't that relentless- nobody appears stressed. Does this seem overstocked or like a bad combo?