Figured it out. There is a base ability at the very bottom of the stela, and it’s very easy to miss. Once I selected that, which opens up the rest of that skill tree, it worked as advertised. But yeah, the UI could use a bit of TLC.
Other than that, though, man, this is really quite good. A few rough spots–the world geometry can get wonky at times, and the navmesh, and the text could use some proofreading (I suspect non-native English speakers as well, though all in all the writing is quite ok), but the storylines, the way things work in general, are really solid. Better in many ways than vanilla Skyrim.
Though so many wolves…gagh.