Well I had Asterina Starfish. Hundreds.
Got a Harlequin Shrimp few weeks ago.
The Asterina's are almost all gone (few dozen left). Now I'm worried about the Harlequin Shrimp starving when he get the last one. Do Asterina Starfish do damage? No idea. I just had to many. Will the tank now stuffer some symptom without them? (like algae grown on rock). We'll see.
I do have Aptasia and I need them (wish I had more growin). They grow in my Sump and make their way to my DT where a eager copperband butterfly hunts down the Aptasia sprouts all day and night. It's a double edge sword in some ways. A year ago the prevous copperband died (probably starved). Soon and he was gone, the Aptasia outbreak took off. Till the next copperband went in.
Bristle worms are in all my Tanks. Never out of control.
But you missed a couple of pests I hate. VERMITID Snails. I've had them a few time and I'll hunt their webs to their location till I get every one. I've see their web to damage to SPS expectially when their are small frags and don't have the height, thus get stung but the Vermitid web.
The 2nd Pest I have in one of my tanks I can't eliminate. COLONIAL HYDRIODS. Nasty small pests that spout up all over the rocks. Looks awful when the take over a rockscape. I tried treatments like Fenbendazole, but it really doesn't kill them completly. I got them under control by no longer SPRAY FEEDING the Corals. Never saw them for over a year+ and forget they were there. Few weeks ago I started Aminos/Coral food. They showed up instantly.
Uh oh Dwight making an appearance! LOLLFS staff who are only there to collect a paycheck are by far the worst pests in this hobby