Have you looked into whether a demodex infestation could even cause these symptoms? I think almost everyone is positive for demodex, so that might be a red herring anyhow.
If all these symptoms started at the same time and some of them aren't even facial, I would think that excludes rosacea as a primary diagnosis, but I have no specialised medical or scientific training.
Maybe you should try another dermatologist or an infectious diseases specialist as well as a neurologist? I'm assuming you're researching what could cause these symptoms; hopefully you'll eventually find something that helps you make sense of it.
I would probably also look into vitamin B12 and D levels if you haven't already, just to rule those out. B12 deficiency could potentially explain some of the neurological symptoms, but I haven't heard of it causing itching sensations.