Madmaggot, people who work do have dogs such as my husband and I and they are very happy as is our little one. It is better a dog having a loving home than being stuck on the streets or in overcrowded dog homes. they just need regular company, toys, cuddles and walks and of course plenty of fresh water etc.
TIA, mine and my husbands dog is just over 1 year old and we got him from a rescue home back in March. He started chewing but he got over it and now realises it is naughty and has been good for about 6 weeks. He gets checked on regularly in the day time, not only for wees but cuddles too, so he knows he is not on his own. We also got him a kong toy which we fill with kong treats and he loves working the treats out. We also got him a nylabone which is flavoured like chicken and it also keeps his teeth occupied. He also loves his tug rope with ball on the end. Plenty of toys like this help with chewing and keeping him active. My husband walks him for 20-30 minutes in the morning, so as yours is a larger and younger dog maybe a longer morning walk would help so he does not have lots of energy pent up. He then has a good hour walk of an evening at least so again maybe a longer evening walk before bedtime would help.
If he is naughty, try pointing to what he has chewed and say naughty and give him a toy he can chew. He should learn to chew what you give him instead. Also before I leave the house in a morning, I make sure the last things I touch are his toys - getting them in the open room, so then if he goes to chew something it will be what I touched last. May sound daft but it seems to have worked.
Being a puppy still he is still going to be in the chew everything stage, but do persevere and over time he should learn. Try and get a routine in place like my husband and I have and hopefully your dog will take to the routine.
Hope this helps.
Good luck xxx