Well, take a feel of a catalytic converter next time you've been driving for a while. I would venture a guess that there is, but not instantaneously. As far as the liquid/stem goes, what you're thinking is exactly what I would expect them to do. There is most likely a liquid trap somewhere in line to prevent liquid phase ingestion into the turbine.
Or they plan on somehow regulating steam flow based on crank speed/turbine speed. I am sure that this would be one of the big issues that would be worked out on the test rig.