Your site design looks pretty good. The two deciduous trees you added to the north of the service entrance are probably overkill since you only need to block views from the plaza.
Your site grading looks like it's almost there, too. The only thing you might verify is the distances of your swales that wrap around the display . You have to take two measurement to get the total dimension, dwg has a good diagram to follow
http://www.dustingoffron.com/ARE/SPDperpendicularswale.bmpHope that helps! Good luck!