Thanks, Madara. I hope to return to this with some more of the angles when I have time. A few of the comments have asked about the US side of things. Things work a bit differently and I recommend you look first at the Authors Guild. We worked closely with them during my time at ALCS and they did some excellent work for writers.
In the UK when we register with a collecting society they ask that we list all pseudonyms to make it easier to find people. It doesn't mean they won’t find you eventually but it’s easier if they already have all the names listed against your work.
I suggest you read back through the comments on this article, especially the ones asking about the USA. I looked out some websites that you might find useful. I just tried to copy and paste one of the answers into here, but sadly my app doesn’t allow it.
Thanks for reading and commenting and I hope that was useful.