How is it safe for helicopters and Ospreys to refuel in mid-air?
That photograph distorts the perspective.  Just Google for "helicopter air-to-air refueling" and look at the image results.  Many show other perspectives from which you can see that it is not possible for the blades to contact the hose or basket - the probe is longer than those on a fixed-wing craft for exactly that reason.





This video shows a CH-53E Super Stallion chopping off it's own probe through over-controlling the cyclic, but that particular mishap would be possible in other flight phases too.