First, it is not very clear from your post what you intend to do with these "powders". Add to compost? "create a soil mix"? Use as a fertilizer? Approximate NPK of these materials is as follows: banana peels (actually banana ashes but very similar): 1.75-.75-.5 coffee grounds: 2.0-.36-.67 fish bone: 1.8-.2-.25 Yes, they can all be applied to the soil as an organic nutrient source. The precise ratios would be up to you and what your current soil nutrient levels are. Personally, rather than going to the effort of preparing, drying and grinding such powders, I'd include the fresh material in the compost along with any other garden and kitchen vegetative waste you can accumulate. Depending on the ingredients, compost can have NPK of 1.4-3.5/.3-1.0/.4-2.0. But its big bonus is the various other micronutrients and trace elements it will contain as well as the textural value and biological activity it will add to the soil.

After doing some more research on humus it's very interesteing. It's my understanding that humus isn't fully understood and very difficult to explain. Just to help understand I've broken it down a bit. Humus by deffinision from Websters is " a brown or black complex variable material resulting from partial decomposition of plant or animal matter and forming the organic portion of soil" comes from "New Latin, from Latin, earth" From Wikipedia is close to the same deffinition "Humus (Latin - "soil ") is the organic material in soil lending it a dark brown or black colouration" And the deffinition for Colloid from Websters is "2 a: a substance that consists of particles dispersed throughout another substance which are too small for resolution with an ordinary light microscope but are incapable of passing through a semipermeable membrane b: a mixture consisting of a colloid together with the medium in which it is dispersed" And from Wikipedia "A colloid is a type of mechanical mixture where one substance is dispersed evenly throughout another." " A colloidal system may be solid, liquid, or gaseous" Aparently if you can let any organic matter decompose basicly with out any dirt it will form a jelly like substance once fully decomposed and in a stable condition. Depending on how well you create humus you could actually end up with nothing. If your humus becomes so stable that it will not provide any help to your plants. I would say this guy just did some research and took what nature already does and is just trying to sell it. I would like to see him actually product this. He may have theroy behind it but no experiance or ability to actually produce this. Take a look at Wikipedia I think they do a very good job explain humus. As far as our own compost. Well keep it cook'n we are still breaking down organic matter into stuff that helps our soils and plants and will eventually allow mother nature to create her own humus. Here is a link that might be useful: Wikipedia Humus

Both likely are not what you want. You want compost made from a blend of greens and browns and nothing from an animal. Mushroom compost has a chance of being total junk so I would stay away from that. You want something that smells like a forest (you'll know when you whiff it) which is a good smell. If it smells like sulfur or ammonia then that is definitely bad. The appearance will be a dark fibrous material that hopefully doesn't clump together too well and can't be mistaken for a bag of moist topsoil/potting soil.

I wouldn't make 'walls' myself. You certainly can if you like, but if you don't want to do much work, you're going to want air to get in there as freely as possible. Large farms often use a bobcat or front end loader to mix their composting manures. At that ratio, I'm guessing it's going to be a slow composting process. If you don't have a machine to mix, then letting it sit for a year will work. Just sift it after a year to remove the larger, un-composted wood shavings (unless I have the wrong image of the shavings in my mind.) You can add those back into another pile. Many people use pallets to make the walls. They have spacing between the slats for freer air flow. Others use wire fencing. I compost wood chips, I use no walls at all... just piles. If you have a 'lean to', or open air roofed barn, as long as the pile stays moist your finished product will have a bit more nutrient value. Covering helps to avoid nutrient loss through run-off from rain. Tarps though, prevent air from entering. Mixing, along with tarping works well, but requires the maintenance of mixing. Some very large farms do anaerobic composting, but that's really a different process and you need to do a bit of research when working anaerobically with manures.