I haven't had time to learn the in's and out's of the unreal engine but I definatly would not have though about using a complex node system to get the hazard stripe sidetextures.
Would just have made a texture in photoshop and a layer that controls the color and then saved out the 4 different texture files and let them use the same specular texture (1 greyscale texture)
and then for the top texture the same thing. 1 diff, 1 spec and a bump (although a bump is not always that usefull on a flat metal surface unless you want scratches and heavy dirt/pits).
I had another look at the first few screens ingame. I would recommend getting rid of the top and bottom ruststripes on the hazard pattern and keep it rather clean with scratching and the brightness not to high.
And having on both sides of the texture a metal strip that gives the indication of a connection between different parts on a higher level using the bumpmap. And then also having those connectors on the top floor texture to break it up and add some interest to it.
Since it is unreal and unreal loves models => create a catwalk in 3ds max with details (connectors and side elements)
Make them with standard sizes (like 128,256 or 512 units long and 16/32 units high depending on what looks best) and have a couple of them with different side details, without sidedetails, different connections between the sections , end sections (have a look at AO ingame to see what I mean).
Could be that you have allready done this but it's hard to tell based on a couple of screenshots
Unwrap them , texture them and then have them ready as modular models that have all the sexy detail for use in unreal.
I'm not really getting the first secret area though:
zulag 1 screens:
First zulag overview
Looking forward to seeing more
edit::
That geometry on the top right of the first secret area is a v shape similar to what you have
here for the electric barrier.
It's a Ushaped bottom part with a rectangular border above that and then a v-shaped support that goes to the sidewall and the above catwalk.
The bottom of the V shaped sollid block that has a trapezium metal plate welded to it right above the rectangular border from what I can see. Behind the plate there are 2 structural rectangular holes that stick out a little bit above the plate and continue behind the plate. and then above that there is a big horizontal square hole that stretches over the V shape block wich gives you an U-shaped top part that connects to the catwalk above.
If it's to hard to follow or if you have problems visualizing it I will draw you a shematic
).
Behind scenes
