After taking, and before presenting your photos, you MUST put them through some post processing to at least level the horizon line! It is no sign of "artistical freedom" to have it crooked here, I shouldn't think so. It just looks wrong.
And a question: who decides on your settings for your photos? Do you? Or do you let the camera decide?
If the latter applies, I suggest: don't. Don't let the camera decide on the ISO it went for here. It's much too high and you get an awful lot of noise. In night photography, you want to go with the lowest ISO, small aperture and looooong exposure. Tripod is indispensible, therefore, but you said in your other post that you do put the camera on a tripod. If that is the case, and you see the illuminated sea bathed in moon light, then why didn't you align your photos right there and then?