The shark'll outgrow the tank
Angles will eat your tetras
I don't think cichlids are compatible setup wise with anything in there
Corys need more than 2 to be happy
Personally i would say yes, but i dont know what your maintenance regeime is?. However i would say that your choice of tankmates isn't the most compatible or best suited to the size of tank but i'm not familiar with all the specimens your keeping.
I would say it is over stocked. Your tank is about 30 gallons and you have about 40" of fish not counting the cichlids and the 2 cats. One inch of fish per gallon is a good guideline to follow when you are new to the hobby.
Also, it's worth noting that the 1" per gallon only applies to small fish (about 3 inches). That silver shark can grow up to 14 inches. A 14 inch silver shark would produce a LOT more waste than 14 one inch long neons.
I agree with the notion that the 'inch per gallon' rule is severely flawed and only applies to a very small number of fish. While I am not sure if 14 neons make less waste than a 14 inch silver shark (but would assume that to be true), perhaps a more applicable analogy might be that a 3 inch pleco will create more wastes than a 3 inch tiger barb. Personally, I wish this 'rule' would be thrown out completely since, most likely, we are able to keep a much larger array of fish in an aquarium than one could have kept way back when this 'rule' was invented.
However, to support the fact that a silver shark really does grow to a much much much larger size than most of us might think, here is a picture I took earlier this year during a trip to the Shedd Museum in Chicago, Ill:
For comparison, that is my hand under the fish and I am a fully grown adult, with fully grown adult sized hands.
Forgive me if this is an extremely stupid question, but what are platerus cats?
Its not about being bombed. He is getting honest opinions to his question. I agree that regardless of anything else, it is overstocked. More info is needed though, in particular, what type of cichlids they are.