bal bla bla bla

perlite - helps to drain soil and helps air flow threw the soil just a lil bit better, helps roots to cling on to something to help the plant hold steady!

perlite is very important in any case!

vermiculite - helps dry soils hold moisture, soil will break up alot easyer, makes it kind of softer helps the roots grow down ward faster for water on dry days.

vermiculite is good to have in pour soils but over all in regular soil its really not needed.

"everyone has their own methods on how to do thing and different strains have different reactions to plants so their for not everyone is right"

????

does that mean that small rocks would work like perlite or does it feed the plants to?

No it doesnt. Just helps drainage, and small rock's arnt really that good. The roots need to be able to spread out and move around, they can move the perlite while they grow, but rocks would give them less place to go, and big roots = big buds and big plants.

so what if you used those tiny polestyrine balls instead? surely the plant can move them even easier...?

Styrofoam could be used But I wouldnt recommend it. I would get a soilless mix ( BX & a little extra perlite to be exact ). Then MAYBE experiment on your own mix. But you will never beat Pro mix on your own without alot of experience.