Does vermiculite really aid organic chemistry in soil mixes?

So im trying to make a nice organic soil mix. Ive got a base soil of peat moss with perlite, worm castings, and possibly some coco coir and bat guano. My question is if i should add vermiculite.

I have heard that vermiculite is very good to have in organic soil because it aids in the organic chemistry of the soil. If i remember right, soil is either bacteria- or fungus-dominant and vermiculite helps it be more fungus-dominant, which marijuana thrives in.

Does this sound familiar to anyone? If not, what are the real reasons for vermiculite in a soil mix?

I can't think of ANY reasons for vermiculite, especially in a peat based mix. The peat is water retentive enough on its own.

I quit using vermiculite years ago as it caused more problems than it solved.

Wet

interesting read on vermiculite-use safety:
http://www.atsdr.cdc.gov/news/vermiculite051603.html

on the one hand, i know it's one of the best media for growing mushrooms (yes, *those mushrooms). on the other hand, it's really rather not-nice stuff to work with (even without the inherent health issues. it's hard on hands AND gloves).

why is it used in soil amendment? the same reason they (used to) use it in insulation: it works and it's cheap. it has good water retention and aeration qualities, it's produced by heating the original mined mica to 8-30 times its original size. for soils i really don't think it does anything the peat moss and perlite aren't already doing.

It is a coarse aggregate mica that is fired up to expand and make a soil amendment from... It is to hold water.... I agree with wet, why use it? I would rather water more to reduce salts.