[hughesjj]

Also for 1., why does the steam have to come all the way back up to spin a turbine? Can't you just have the Turbine down the shaft too? I get that there's other tradeoffs than that, but I figure the closer to the source the less leakage/parasitic loss there'd be

Unless the concern is that there's too little energy after going through the turbine that the water may condense and fall back down the "wrong side" of the pipe and add a bunch of resistance to the turbine.. although I'd imagine it might still be cheaper to do some one way valves and pump out the drainage pans while still being a net energy producer