Yes. 

... 

Oh, no. It is not a macro lens. Thanks for your kind asking. 

You can of course choose shorter exposure times because of the open aperture, which may be an advantage in the shade, in the evening or in dark corners, especially if you are taking photos without a tripod. Where desired, the bokeh is also a dream. The depth of field can really play off best in strong foreground-background contrasts, such as in portraits. It's possible that the crop factor, e.g. with small format cameras like my 550 D, ensures that you get a slight telephoto effect, i.e. you might not get a complete sky on it at all. 

I had to wait for a clear night. I tried all of my binoculars. NONE were suitable for star gazing. They magnified the dark sky. On a tripod you can see a speck of light.