Oh my gosh, I didn't see the pictures before, they are adorable!!
For corners look up "how to make a dig box" and then put one in any corner they are digging/chewing at.
The bed is the easiest, simply put something between the bed frame and the baseboard. This can be a piece of wood, wire grates, storage container lids, etc... If you find something long, thin, but high enough to reach the bed frame then all you have to do is push the bed against the wall and no one will even see it!
It is their nature to dig/chew behind things and in corners. I thought my rabbit was being smart by chewing things I couldn't see, she wasn't, it was just her instincts to chew in those places!
So giving them designated places to do so will allow them to get some of this desire out of their system.
Lastly, for chewing, I recommend pure timothy hay pellets, and/or timothy hay cubes. I get the pellets from my local feed store. They are dirt cheep, less mess, great for dig boxes where you sprinkle in pellets, treats, or herbs, and really satisfy that need to chew! Just make SURE the only ingredient is timothy hay because those can be free fed. One cue to let you know they are only hay is that they are much larger than any other pellet.