Yeah, noise is not a minor issue. The other way to reduce the negative pressure is to have intake hole/s big enough not to cause it or open the door a bit when light's on.
Off the floor is best so that any roots that poke out of the bottom will naturally air prune and not bind themselves in the pot, which will also encourage the formation of more roots higher up in the pot.
I believe with orgasmic soil ( :) ), you should let it 'cook'for a good while before you use it. The critters need to break it all down to plant-usable form. What you are smelling is that process.
Total ignoramus on coco. Going to try it soon, so learning what I can about it. All thoughts and suggestions are welcomed. Also, would air-pruning pots be best and what size for up to 1metre-ish high plants?
Read the dosage section in this link from a UK company I use and see what you think you should use but you should only need to do it twice as the whole point is to just inoculate the roots with the endo-mycorr species and then they populate within the roots, forming a symbiotic relationship...
There seems to be more expertise here in coco-style, so that's probably the way to go for me. Just got my Ionic hydro grow. looks Like I'm going to get the coco-version now. :)