Yeah, "necromancer" has some connotations that I don't particularly care for, particularly as they relate to the use of rituals involving dead bodies and such. "Medium" feels like the best term to me for what you experience when you feel non-physical beings present.
The terms (empath, clair-whatever, medium, shaman/healer, etc.) are actually quite distinct, but in my mind,where they all blur together is in their use. Most people who are sensitivetend to besensitive in more than one way, sort of like an athlete who is good at more than one sport. Take me for example. I'm an empath, but also have a bunch of the "clair" talents and am a medium too. When I use my abilities, though, I don't approach something like, "Okay, today I'm going to just be an empath." They all run together into one thing: my experience. For me, there'slittle value in trying to separate the abilities into different buckets, sort of like how I'd rather do push ups and pull ups at the gym rather than separating each muscle group withthe chest press machine, the bicep machine, the tricep machine, the lat machine, and so on. Musclesare made tocoordinate and work together, and I think extra-sensory abilities are the same way.
If you're looking to get a better understanding of the different areas of extra-sensory experience, however, a well-stocked "new age" bookstore might be a good place to start. Even a good-sized regular bookstore will have the basics. I recommend actually going to a store for these types of books, rather than ordering online. A book that resonates with someone else may not be right for you, and vice versa. Being able to hold the book, peruse the table of contents, and readcertain sections of the book before buying is important to make sure the book is a good fit for you. There are lots of ideas out there about "the way things are" in the extra-sensory experience, and they're all correct in a way, and all incorrect in a way. Finding what's correct for you is the key!
For me, doing the research was also helpful in that it enabled me to recognize the broad areas in which everyone does seems to have a basic agreement, because these areasthen form the foundation or common vocabulary fortalkingto others with similar abilities, sort of like how all English majors tend to read the same books, and so on. It may not be important to distinguish between clairsentience and claircognizance, for example, butI have found ituseful to know things likewhat a chakra is and how it works, and how differentschoolsof thoughtconceive of the various categories of spirit beings. It just put more tools inmy toolbox.