(1) Mushrooms are an experimental idea, I'm not really committed to as I am to beans and someday (THC-free) hemp.
(2) A 1,000 pound cow produces an average of 10 tons of manure a year. It would take a lot of mushrooms to equal that.
(3) The stink factor probably depends on the species of fungus, I'll bet some don't smell at all.
A couple little mushroom logs probably wouldn't stink at all. Filling half your basement, in your optimistic fervor which translates from unlimited racks (previously mentioned by you) would be awful.
Growing for personal use, people typically use a damp hay medium, or logs. On a larger scale, they use hay and manure, probably peat and other stuff. It stinks bad in any large scale. The small hay blocks aren't cost effective when you get beyond a hobbyists scale. So it'd be a nice way to supplement your diet, you'd probably have a little setup about the size of a 50 gal fish tank. Bigger than that, you'd have to make less costly adjustments thus comes the stink.
Dude, I'm telling ya, you can smell mushroom houses a mile away. They look like little concrete office buildings, and every 45 days or whatever, they harvest, churn up the shit and its bad. You wouldn't want those sorts of beds in your basement.