OH NO SIR PLEASE DONT RELEASE YET. Cashworks is an excellent map and you have done a wonderful job, and yet I see you think you have optimized as much as possible! I am sorry to say this is not true
That's ok though, optimizing is very difficult!
I want to help! I did a quick inspection of your map and at first glance see many possible optimizations! Below are many paintovers to show you some things that are possible.
For starters you really must get a better handle on the overdraw! There are many places where hidden or all but hidden faces are not nodrawed, where props are being rendered and where func_details could be func_lod's. I know what you are thinking, "func_lod is awesome new entity but it has alot of computational overhead!" this is true, however many places in your map could benefit from it's judicious use.
While your hinting is quite good it does leave alot to be desired
You have forgotten the power of angled hints in many places, and are not splitting high action/view areas and vertical spaces enough! I have done some paintovers that might give you a few ideas.
Also in some places, vis could be controlled better simply by better "filling in" space (especialyl behind displacements) and further hint shaping from there.
Controlling the vertical could be very important to you. XY hint planes and large func_viscluster volumes will group the upper outdoor leaves into more efficient clusters.
Please keep working. You can do it!
Photobucket gallery of paintovers for optimization:
http://s136.photobucket.com/albums/q192/MrHappy_photos/please optmiize cashworks/