You should add to all houses func_areaportals and to all windows some func_areaportalswindow
You already have quite a bit of fog so i'd suggest you change the draw distance of all props to around the same value to make it look seemless
Then you should disable shadows and self-shadowing to ferns and bewshes
The best method to optimize your map is to use func_occluders,
which i recommend you add to all the bushes separating the pathways.

I think this could even be something different... like a stealth gamemode
With a time limit of 5mins and bomb fuse time of 1s
Something along the lines "Hunted"
CT the hunters T the hunted.

Maybe people should adapt instead of trying to change the map?
Play slow, play low... there always seems to be a safer way...