Hi! I hope im not too late! I want to start off by saying that i DO NOT think you should put Buster to sleep! I understand it can be overwhelming and scary to have a dofg behave the way he is but putting him down is not the answer! I also understan that you say oyu do not have the time or skill to fix him but the most important skill that you need is PATIENCE. To help get in tamed you need to become the leader. he need to know that your the boss and he has to follow your rules. You can do this by starting off with small tricks and commands such as “sit” “stay” “come” “laydown” ect. Then give him harder one make up your tricks or commands as you go as he learns to follw he will learn to listen to YOU. Teaching them trick isnt too hard n it does take long. Once he is listens to you and you have comtrol over him you can have control when he becomes aggressive by telling him “stop” or “stay” or how ever you choose to use your command wording. Another tip dogs respond better to calm stern voice not one that is yelling. You stay relaxed to keep him attentive and relaxed. As far as for when company comes over I would suggest putting his leash on so you are able to tame him if he becomes aggressive but allow freedom untill he seems to tense up. Give him time to get to kno the person who has come over NO PETTING untill Buster seems comfortable. When he comforable all will b well. When you be the leader of him, all he’ll want to do is please you and his good behavior will reflect that.