Agree with Gingerling. Maybe discuss with the owners, & other family members about the growling. In our house our Cashew did a little growl (while in our bed), ONCE. We immediately, said 'NO'!LOUDLY, while making a "Mad Face". We did nothing else, did not remove him, after about 5 minutes, we all resumed being happy. He has never done that again. V's do not take criticism, or negative training well at all. A simple correction, then resume loving them.
We also are pretty lax with Cashew, he is allowed up on the couch, beds, etc, but he is a very well behaved dog. It is very important that you know that it is a Vizsla's nature to be WITH the humans all the time, that is probably he is insistent on comining into your bedroom no matter what. LOL, I do know what you mean about them crashing on the door till they get in. We lock our bedroom door when we do not want him in there. He will try the jump hit the door lever once, if it does not open, he knows it is locked, & he goes and settles somewhere else till we come out. Consistency is the key.
It would help you feel better about the dog if you read up on them. You would know what to expect, as they are very intelligent, loving creatures.