This map is looking really good.
I usually play alien, and wall decorations are often a pain, ATCS is one of the best maps for wallwalking, but it has extremely plain walls. The main advantage of really plain walls is it allows for conrolled, erratic "corkscrewing". This is even better than usual dodging, because the dretch is just going everywhere. Decorated walls make this maneuver very hard. (However, the walls do a look a lot cooler.)
Arachnid has good, alien friendly complicated walls. You'll notice most of the decorations in Arachnid are vertical. This allows shooting to the ceiling and hiding on the wall behind a bulkhead. I particularly like this config, because it lets me get into a nook above the humans' head height, and wait for one to pass (then, drop and follow, grabbing a couple shots before he can even see me).
The ability to get under the floor boards is cool, however, it looks like you can shoot through it. Are there places which aren't grating where a dretch can take cover? That might be worthwhile. Is it easy to get back out to get the drop on a human?
Don't deconstruct all your hard work on my advise though. It looks good, and these considerations don't effect bigger bugs.
When moving as a Maurader, lips and overhangs are the most annoying things to me. Stretches of plain vertical wall next to and below platforms are great for Mauraders. In transit, instead of taking the stairs up to the human base (where the three donut balconies, the bottom one with the busted floor are), I'll wall jump up the flat area right next to it, you can quickly get up to the third platform with just a few attempts. Then you only have to take the last platform.
The platform above the alien base in arachnid also has some similar tricks. You can launch over the door (to the ramp) to get there, or you can head over to the other side of the OM platform and shoot up that wall. This is kind of delicate, because I often overshoot the whole platform on last jump.
Anyway, my point is that long stretches of relatively flat wall (any direction, so vertical decorations are nice here too) will allow a Maurader to travel very quickly along it.
Dragoons just have a built in rocket hop, so designing for them is not much different than for normal maps or speed trial maps.
Tyrants don't like ladders. Or raised platforms. The default human bases on niveus and tremor are both very nice for tyrant rushes. However, don't get stuck downstairs with a tyrant on tremor. There's no way out. Not that that is bad. It keeps the S3 aliens on their toes.
These are just considerations and things to be aware of. Either design to block this stuff, or design to allow it (usually want to do both, if you want areas that are friendly to one side or the other, and you would usually want both on the same map, for balance).
Anyway, I'm looking forward to this map. Keep up the good work.
Jeff