Andy, thanks for your great observations. Is the main drawback of the alloy steerer on the fork the added weight? It seems like at least it would be less susceptible to cracking from overtightening. I read a review that praised the bottom bracket screw system, but I don't know much about it. I've never owned a single speed bike, so I'm not familiar with eccentric hubs/bottom brackets. I had thought that another option would be something like a White Industries ENO.
It looks like there is just a plate without a hanger portion that fills the spot instead of a full hanger. It does look to be a relatively simple, straight forward frame. But hey, it's $529 for frame and fork.