You had me at hockey. Where is this project at? First thing I see is that on the side of the seating section your geometry is still on the side. (where it is gray and red striped) You can reduce the geometry by erasing those lines that will not be seen in final model. Will help the model to continue to be manageable as it continues to become more and more complex. The other thing is if each of those sections around the end boards radius have similiar seating you can make it either a group or a component and array it around the curve. Then just make the minor adjustments on each section instead of having to build each from scratch.