I can't see the picture on my phone that well but the torch doesn't look like a goner to me. Corals eat and defecate from thier mouths, that might be all it's doing although it is a large amount of brown gunk. Is the torch in a lot of flow? Torches will retract if there is too much or not enough. Don't move it every 20 minutes though....give it a couple days to react if you move it.
Get a different ammonia kit. API is pretty notorious for false positives, but if that is a true ammonia you have an issue.
Meanwhile I would focus on stable water parameters and regular ( but not crazy, maybe weekly) water changes. Slowly adjust your salinity upward to 1.025 or 1.026- research this forum for how to do it right. Read lots of info about how to keep your tank stable in the "New to the Hobby" forum.
I wouldn't move your tank now if you can avoid it.
Get a small cleanup crew. If your melanarus eats the cuc get something different next time ;) FWIW, my Mel doesn't bother the snails or crabs at all.