I have to agree with Tanza here, your dog is definitely resource guarding. This behavior is unwanted, and can be disastrous if left unaddressed, or not properly handled. I had the same issue with our Bolt when he first came to live with us at 6 1/2 y/o. We have had him now for 6 years. I have worked extensively with him, but it is an issue we have to continue to deal with on a daily basis with training. I believe he had to be rehomed because of this issue. When he first got here, he thought sleeping in bed with me was his right, not a privilege that I gave him. He would not allow my husband to get into bed without charging/snapping at him. Clearly this was not acceptable behavior. If we were in bed, Bolt and I, and my husband then came to bed a while later, Bolt and I got out of bed, let my husband get into bed. Husband would then call Bolt up onto the bed tapping the mattress saying 'big bed'. Once the dog was in the bed my husband would have a few small treats and would work a little obedience with him before bed. Now when Bolt sees my husband coming to bed, he knows he's going to get a treat and do a little obedience. BUT even after all this time, if I'm asleep and the light is off, Bolt will growl at my husband. If the light is on, however, and I'm asleep, there is much less chance that he will growl at my husband. My husband watches his body language very carefully.
As far as chewing things....our first pair of basenjis were crated until they were 8 years old when we left the house. I had to remove a chair to a back room because Tim liked the cherry wood! Our female does not like to be left alone, although she has Bolt with her, she wants us to stay home. She will show her displeasure by chewing something of mine, glasses, ear buds, or will move my shoes to the middle of the living room. I try to keep all items out of harms way. It comes with experience and training you. Don't leave stuff out that she can get into, or chew. They have no trouble finding stuff on their own. Some basenji owners will give cream cheese frozen in a Kong for their basenji to chew. Ours just thought it was this weird thing, licked out the yummy stuff and ignored the Kong. It's frustrating, we all know, we have all been there, but be patient, and above all consistent. They are independent thinkers, what works for one doesn't mean it will work for yours, sometimes you need to try different things. Hang in there, it's so worth the reward!