The list of neglected fields in Western occult tradition is so long I could fill a good-sized post with the list. The current occult scene is aware of maybe ten per cent of the total tradition, and the other ninety per cent is forgotten or fragmentary. How many people know their way around occult musical teachings in their ancient, medieval, or Renaissance forms? How about the interface between astrology and healing, or between astrology and architecture, or between astrology and warfare? How about the esoteric Western martial arts? The site you listed, exploring Germanic astrology, is a good step in another mostly forgotten direction -- there's an immense body of European esoteric starlore distinct from the astrology imported from the Arab world in the high Middle Ages, and very little is known about it.

The neglected branches of occultism that matter most to me right now are the ones I'm working on relaunching via the Golden Section Fellowship: sacred geometry, classic occultism, Western internal alchemy, the interface between occultism and what's been clumsily labeled "earth mysteries," and the temple tradition I've been chasing down for all these years, for starters. Those aren't necessarily the most important of the lot, just the ones that fascinate me most. There are hundreds of others.