When is a German Shepherd physically/mentally mature?
I'm not sure if the title is the best way to phrase my question. If this post turned out to be a rant, I apologize in advance.
We have a one-year-old German Shepherd, who's of course a little troublemaker at this age. We're told that we need to exercise him and give him mental challenges, or else he gets bored and becomes destructive. I take him to the dog park every weekend (Friday, Saturday, Sunday) to socialize. I play fetch with him each morning before work, making sure that he's exercised to the point that he'll walk to the ball and flop down to rest because he's had enough running. I leave him with a kongball full of treats and other toys while I'm at work. I take him to doggy daycare two days a week. He's currently seeing a trainer every week, so after work I practice with him the new skills that we learn from the trainer.
With all of that, I still feel like he's not exercised enough. There are still days that I come home to find a corner wall being chewed up or papers being shredded, and mornings that I wake up to his bed being torn into pieces. My husband has been abroad since September and won't be home until the summer, hence I'm the only one taking care of him. It has been a lot of work and a lot of stress on me, and every time I raise my concern to people on the internet, I get a "you should rehome your dog if you can't give him your time and attention." We've been pretty depressed ever since my husband left, and we need each other's company. I keep hanging on and telling myself that once my husband is back, everything will be better, because all of our lives were so much better when he was here.
Anyway, will there be a point that my dog will be perfectly content being home by himself? I won't have to spend hours running him and giving him my undivided attention when I'm home. I can walk him in the morning and play fetch with him after work, and I won't see any signs of destruction from him. I won't have to take him to daycare (or maybe once a week instead of twice a week), and he'll be happy with the toys at home while I'm away. Will there ever be such a point?
I'm only asking because my husband and I are planning to have a baby in the near future. We don't want a baby too soon that we'll have to eventually rehome our dog because we can't make time for both the dog and the baby. We also don't want to wait too long, because we want to maximize the time our baby have to grow up with our dog.
Is there a sweet age in dog that having a baby would be okay? An age where he'll get along with the baby and won't be sad if we have to devote our time with the baby and not with him 24/7? Of course we won't neglect him, we'll take him on strolls and to the dog park with the baby, and we'll play fetch with him while baby's enjoying the fresh air. But we want him to be okay if we spend time holding our baby or changing diapers instead of petting him.