But back to Ambient, I thoroughly enjoyed the Wongraven, Spectral Lore and Forgotten Kingdoms links you shared. Especially Spectral Lore which I plan to now get into!
I think Burzum's Dauði Baldrs is absolutely essential listening in this realm of music and to a lesser extent, Fenriz's Neptune Towers project.
Here's a few of my personal favourites for good measure.
I liked your 2nd, 3rd, and 4th songs. You did prompt me to listen to Daudi Baldrs, which I hadn't heard since before Belus came out (and wasn't a fan at the time since I saw 'War' as the pinnacle of his writing at the time). It grabbed my attention this time for sure, especially opening with the title track, which is pretty much the same thing as Belus Dod. \m/
One of my favorite finds last year was Locrian's collaboration with Mamiffer "Bless Them That Curse You"
Drone isn't so much a specific genre as a way of making music. You get metal, ambient, 'new age', and whatever else drone music.