Re Sony Tethering: Sony and Phase One are now pretty closely in bed for software - Sony has purchased, in bulk, enough C1 licenses for them to include Capture One with many of it's cameras (naturally they didn't pay list price for these many many licenses, but it's still a very significant investment).
I do not have any inside information (we don't sell Sony so this is not an area that I have much interest in), but it doesn't take much imagination to think, having just bought a boat load of licenses for C1, that Sony has a lot of motivation to provide a better SDK such that C1 can then provide more tools like camera control and Live View. Their OSX/Windows SDK so far, only provides for rudimentary access to trigger the capture and transfer the resulting file.
I'm quite sure that if/when Sony provides an SDK that allows such functionality that C1 will be fast to adopt it.