It's a pity that DarkPlaces doesn't deal correctly with the borders of animated reflecting surfaces. This white "noise" on your second pic doesn't look very good imo. Have you thought about replacing the water with a simple mirror texture (not animated) or a semi-reflecting floor (me thinks about ths starship-floor-effect without the transparency)? I believe it could fit the theme and support the marble look you've got going on there with the floor.
And please choose a more trim-like texture for the arch in the last pic. The organic looking rock-texture there doesn't fit the architecture. Some outlines at the edges do wonder
Overall i really like the style. Nice and fresh approaches. And i know how difficult it is to create some convincing textures. That's one reason why i never really did textures on my own. The textures you made are better then everything texture-wise i ever created

Can't wait to jump through this halls.
bleach->aneurysm->straledm5->dieselpower->space-fun->o-fun->runningman->runningman1on1->aggressor(conversion)->soylent->bloodprison->bluesky->ruiner->reslimed->strength