3DSMAX 2009 with Mental Ray

This is the rendered scene:
[Link to i903.photobucket.com]

I premise I'm a mental ray fan....but only cause I've never understood VRay!! >.<

To be honest, there are several problems I've encountered, in this project... =p
1). If you pay attention to the volume light rays, you'll notice they're distorted each time they pass over a depression between the "rocks" that compose the wall behind.
2). I think the volume light rays are too "heavy", but lightening them seems to take some depth off them. Is there any way to limit the volume light along the light rays without shortening the far attenuation? I mean: is there some way to make the fog to "cross" the light, instead of being part of it?
3). I'd like the water below to cast some caustics, but seems like there's no way, not even with a displace map, to make this surface to reflect caustics toward the camera >.<

Please, take the "pile of dirt" in which the sword is speared as it is, I didnt work much on its poly and texture...
About the light, it's a regular spot, multiplied to 8, with a "sun through a tree" 2bit texture to simulate a tree's shadow....
The well's wall is just a stupid tube with a displacement map I've drawn myself, nothing special....
The "water" is a regular box with physical glass and displacement map....
The sword is "another pair of sleeves" as we use to say in italy: it's made of 5 objects (grip, grip cap, blade, inner blade, snake-like spires) and includes a physical glass material. The blade is a simple bevel of a mirrored spline, the grip is a deformed poly of a cylinder, the grip cap is a lathed spline and the snake spire is a (always appreciated) loft.

Hints, tips, tricks, critics and whips are always welcome!! ^o^
And if you're going to tell me to move to VRay, be prepared to be my personal tutor!! >o<
Thank you ^.^

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No Gods but Yourself!! >.<