its not terribly off the mark.. you're on the right track at least. using guide lines for the perspective is a good idea, but im not so sure the posture of the guy in front follows them well. the POV looks as if you're lying on the street looking almost straight up.. he should appear to 'slant' as the buildings do.. even if he is slightly leaning backward.
as for the lighting, the entire atmosphere seems flat. considering the tree's size and all the lights and its proximity to the viewer, there should be lots of influence from these lights on the foregraound and the guy. the moon should illuminate all else from above, but since the helicopter and tree top are in front of it [absorbing moonlight] there should also be a shadow cast down from it. and dont forget the reflected light from the buildings [and any office lights thru the wndows]
this could get difficult [depending on your skill level of course] as to how detailed and accurately lit you'd like this piece to be. its an interesting idea and you've selected a chalenging perspective, but doing it correctly will be rewarding.
on another note.. NEVER fully stop line drawing. you may not always use [or scan] your line drawing to paint in PS.. but you should ALWAYS use it as a guide to direct you while painting. the better and better you become at describing and laying out your ideas, the easier it will be to transfer those ideas to digital and maybe change things along the way while painting. but your drawing is always your foundation to build upon. keep practising, and keep posting.. - JAG
it's only after you've lost everything, that you're free to do anything..