Zone Creation Model/Texture issues

[OrisonSeven]

Ok, so our team has been hard at work for some time now comming up with some very detailed (often way too detailed for the game engine) meshes and textures all complied into a few zones we have been developing. There have however, like any undertaking, been some snags:
1. When using openzone/.s3d files, with 3dsmax texturing, are bump maps supported (for those who dont know bump maping, its like adding shadow texture to a flat texture to give the illusion of 3d) ?
2. When making trees and other foliage, the use of 2 sided planes (a plane with the same texture on both sides so as to keep polys low while creating leaves and realistic trees) doesnt seem to work. In other words, when rendering within max, the trees are correct, but while in game, only the primary side of the plane shows up, the secondary (back side that is typically black within max) is invisible. This results in 1 of 2 solutions both are very annoying and cause the poly count to increase. First, we have tried simply sticking 2 planes together ontop of one another, which doubles the poly count, and seems a bit excessive, and having them face opposite one another. This does fix the problem but doubles the polys which decreases preformance drastically. The second is to just use more planes all mangled together so that the clear sides arent really noticable (they actually really are). So, back to the simple question, Does openzone/.s3d support 2 sided polys, and if so, what could possible be the issue?
3. Is it possible to create an object but make it have no actual physical aspect to it, so that players can walk through it (i.e. fake walls, leaves and bushes that can be walked through, blades of grass, and so on.
4. We do wish to sue simple client because the use of animation/animated objects and things within the terrian would be huge. (some examples, static mesh with an animated texture for a waterfall with a particle/animation of spray where it pools, the ability to add some form of animated objects such as leaves falling from trees every so often, or zines swaying with the wind, to even the use as smoke from a fire).
5. We have a sound artist working to create alot of custom music for the game including overhalling some of the songs into new versions for a feeling of nastolga while traversing our lands. Can songs be used within certain parameters or zone wide and baked into the files so that we can with the use of a patcher, distribute them to people wishing to venture into our world?

We have had some success with ingame content, or rather importing and creating a zone as I will include a very and i will push the VERY, basic and raw version of a raid style zone that is reminiscient of Kelethen meaning there are tree top platforms, but rather then a city, it will be a massive arial maze of platforms that contain creatures that look like a merger of a goblin and an oversized gorrila called the Augrom. The idea will be for this to be for both small parties and raids becuase of the easier more open forrested area before getting to the elevated maze. We also are going to include alot more foalige as both barriers and to create the feeling of actual jungle. Also, alot of the textures are still in there first rendition or are acutally just textures that are thrown in simply to allow for a feel of the enviornment.

Images comming as soon as I recieve them from the tester.