Here's what I think. You have nice fish but there's too many in there, and fish that wll outgrow the tank. I like Severum but they will get way too big for that tank which looks like what...a 30 gallon? Same with the loaches. It could be a growout tank but you made it sound like it's your only tank.
Another thing, take out the African too it doesn't belong with CA/SA's imo.
Next, the marine background (with yellow tang included) doesn't go well with your freshwater setup. A simple black or blue background will show off the fish more.