If loosh is a dark energy, and it gets transmuted by our requesting this, and becomes no longer useful to the spirit meddlers to enable their survival, would this be a karmic misstep as we are supposed to help heal them, not kill them?

You cannot be blamed for wanting to better your circumstances. The fact that the spirit meddlers are present and taking advantage of a lowered state of being, and fostering that in their human hosts, puts them in the line of fire should there be a divine intervention to assist the human beings who suffer, and thus make them a less desirable and safe environment for the spirit meddlers to exploit. We see that as entirely their own karmic consequence when they set out to be attackers and infest living humans. They had no right to do so and were violating the sovereignty of human beings to intrude in their energy and sabotage them. Human beings have every right to seek healing for the dilemma they created, and if it costs them, that is an appropriate karmic consequence and is not a penalty for the human hosts who only want to live their lives on their own, as they have a divine right to do so.