Op YANBU.....
I have had large dogs all my life
They need a couple of hours off lead exercise with training too.. daily, every single day come rain or shine.
They need constant supervision and training for the first 6 months or so. Then still regular training.
They need to be crate trained, so wherever the house they are in is they can go to or be put in a quiet safe space for a period of time, ie whilst family are eating if they will not behave around food.
That is just the begining, if he is not doing these basic things now this is a really big issue.
I am looking at my current 6 month old pup at my feet, and thinking of the many , many hours of slog to get him to only chew his toys, sit under the table whilst we eat, not go upstairs, not jump up, come back when called, let us know when he needs the toilet.
( he has not had an accident since 4 months old)
This is not normal healthy dog behavior, none of my large breeds has ever chewed, skirtings or doorframes, or flooring. he is underexercised, undertrained, and frankly it is sad to hear....also this is not a type of dog you want to be undisciplined as he must be very big and strong.
Your Dp sounds incapable of taking proper responsability.
I would not tolerate my house being damaged to a fraction of what you describe, by even my own dog!
Sorry op but l don't see a future here.