Clown Loaches get huge. Angelfish will eat anything small enough to fit in their mouths, and they reach about 6". Severum, I don't know much about, but they get fair sized as well, and they're mean, aggressive predatory mean. The yellow ones, I'm assuming you're talking about Yellow Labs? They're Mbuna, but they'll also eat insect larva and crustations, so I'd assume that they'd eat anything that they can catch. Mbuna are hard water fish, everything else on your list is more soft water. I'd recommend smaller cichlids instead, like Rams, Apistogramma, or Kribensis with your current stock. They tend to stick to the bottom, and only get about 4"-6", the male Kribensis being the largest of them.