The bedding does all the things you listed, keeps bugs down, and additionally is a fine way to recycle cb and newsprint. I think corrugated cb's high surface area is a large factor of its value and why it turns to castings so rapidly.

A thriving bin will regulate its own temp and moisture, so wouldn't need bedding much. Still, its double duty as foodstuff eases the nerves of folks who don't check on their guys often. I know it does for me, since I'm often away for a week at a time. I can take one look at the shredded cb under the whole cb and tell what the worms have been doing with their time, and whether or not they need more food.

Sorry to ask you a question, but I am wondering, since you don't add any bedding do you just feed kitchen scraps until the bin is full then harvest the castings?

This link http://www.redwormcomposting.com/worm-composting/worm-bin-bedding-in-more-detail/ might be helpful to you. It seems to imply that regular addition of bedding is needed for the worms and to maintain the environment.

As far as I can tell, the whole "nitrogen-carbon" "green-brown" balance thing doesn't really work the same way in a worm bin as it does in a regular compost pile. And worms certainly don't "need" to eat paper, or cardboard, or leaves, to be healthy happy poop machines.

The main purpose of bedding in a worm bin is to keep the environment in the bin permeated with air. You want the food materials to be decomposing aerobically; the other living things that process the food before the worms can eat it need oxygen, as do the worms themselves. Compaction and lack of oxygen within a mass of moist food materials leads to anaerobic conditions, producing noxious compounds that harm or kill the worms. The texture of the bedding, and the fact that it contains cellulose which is slower to break down than other nutrients, allows the bin to stay aerated throughout. It also absorbs excess moisture rather than allowing it to pool up.

It's possible to maintain a worm bin without bedding IF all the conditions work out such that the materials do not become anaerobic. Perhaps the volume of new food being added is not so great, or it's mainly on the dryer side, or it's of a texture that allows air to permeate through it, or it has lots of cellulose in it already. But it is much harder to luck into this combination of conditions without bedding materials, especially in a plastic bin kept indoors.

Bedding, in my opinion, is simply the primary food source for my worms. I don't give them much in the way of food scraps, because we don't leave much ourselves. Used coffee/tea, banana peel here or there, or a cantaloupe shell, egg shells, maybe some leftover pet food, now and again (but that tends to breed mites too easily) and waste paper, or stuff out of the yard composter. I swap the bedding out, either partially or fully, when the bin is fully processed enough to suit me, and add to it or otherwise manipulate it with additions (cardboard, mulch, compost, peat, leaves or leaf mulch, mushroom compost, or shredded paper, whatever) only if there is an acute problem, like flooding, or if worms don't seem to be thriving as well as they should be.