Ran around this a little bit, intended on giving you clipping feedback, but it's all looking pretty solid! Didn't really see anything stand out at all! Good job on that!
Couple things I noticed, otherwise:
You have a ton of space under your displacements that are being rendered. Bring your maps floor much closer to the ground itself, and clip/ nodraw any large textured faces that aren't visible from above. The former will save you some headaches with VVIS, while the latter will save you filespace/ time spent processing lighting.
To get rid of these water seams, assign the same cubemap for both the water faces on the map itself and in the skybox.
I'm not a fan of the detailing on this structure. At the very least I'd give it some contrasting support beams on the inside to add a little more believability to a otherwise unrealistic structure.
Your entire mid and both second areas are rendering when standing on either second. I know you're working on optimizing now, so this is something I'd focus on. A big occluder on the wall I'm pointing at in the first shot would help you out, but I'd try to get the leaves to not render first. Some angled hint brushes might help you out here.
These occluders are pretty good, but I'd get rid of that little gap in between. You'd get rid of that line in the middle that is still unnecessarily rendering.
(don't worry about the checkerboard, that's on my end) This occluder is useless. Your visleafs are good enough from this area looking outward that nothing is rendering anyway. I'd axe it.
Some nasty zfighting on this gutter.
Massive epic chrome pillar leading to tiny baby stock laser is super anticlimactic, imo. You should try to get something custom made up for the top of this to really make it a set piece for your final.