Neat design! I like the looks of that clay based membrane; do you have a notion of what it will cost you?
I like the idea of the compartmentalization... to a point. It would certainly
be nice to have that degree of sound insulation between bedrooms and living areas. But doing it for 6 spokes, sure, it lets you use 8" logs of relatively short length... but man, you're going to need a lot of them with all those walls!
As far as wind resistance goes, it seems like once you add in the sloped, outer portion of
berm extending out past the 'spoke' ends, you're starting to form a partial wind-trap; the ability of the building to let the wind flow past, was better as a simple dodecagon...
As far as
energy efficiency goes, I`m not sure you`re doing yourself any great favours with spokes in all 6 directions, especially not if the intent is for full height exposed outside walls on the end of every spoke. Why not either
skip the 2 northern spokes in favor of a semicircular rear wall bermed all around, or berm around the spokes? Either entirely, or enough that only a window opening remains? You're still going to pick up lot of light from windows starting 4 feet up. I think I would try for at least 1-2 windows, quite short but as wide as practical, around the bottom edge of the central hogan. I think you could lose a lot of your outer spoke glazing and still 'feel' brighter/more open with a fraction of that glazing in this location. Do you have much snow to worry about?
(And if you're berming around them... why not use the in-between spaces for additional interior space..?)
My limited experiences with structures with lots of thermal mass, suggest that it's not that necessary to have so much surface area, to see the benefits. And if you don't need the surface area, its more time/money/hassle/risk than the same space, with less surface area, all else being equal. You can pick up thermal mass outside the structure, with your membrane, drainage, and maybe some insulation...
..I guess I should note, I'm picturing an excavator and ground that is possible to excavate. If you've got a mattock/wheelbarrow, and bedrock, I don't think my suggestions apply very well unless you can find some dynamite...