next time you post images please post them all in one post.
you need to work on not centering your subject so much. if you put his head (number 3, for instance) higher in the frame and put him on the left or right side of the frame, it would have seemed to fill the picture more...also, he will seem more like he's a part of his environment, not just slapped there.
as for the lens issue...it's very good training to get a wide angle lens and get REAL close to the subject - almost so that it fills half the frame. you will most likely need to ask permission before doing this. this will train you to be comfortable taking pictures of strangers, and can lead to more intimate captures also. if you don't want to do that, you could always get a longer lens (anything above 85mm).