The rule of thirds is a beginners photography rule that most people dispose of after a moderate amount of experience. Its to make otherwise plain photos a little more stimulating, not a concrete rule that must be followed as all times. Honestly, its the last thing on my mind when taking a photo.
^by rule, i mean its more of a 'tip' really. this picture just needs to be cropped thats all, to get rid of the space above him and to cut out just a little of that wall to his left.
i duno man, the negative space works. its where the subject is looking, you follow his eye line and thats the negative space. i think its fine, no cropping needed.
perhaps. its not that its a bad photo, in fact its an engaging photo, but i think something could be done to make it better, i just cant put my finger on it.