If he's left home alone and confined all day he's probably lonely frustrated and bored and when he gets out of the bathroom he lets out all his frustration on your chairs, shoes, furniture, etc. Some of that is normal puppy stuff but if it's extreme you may want to try something different. If you get him fixed that will help with the humping. Try to be patient as puppyhood can be trying at times but well worth it once you learn what works with your puppy. They are all different
Best wishes!!