Regarding #5. EVERY dog owner will tell you that there are words their dog understands. If I ask “Do you want to go for a wee”? Rassilon racing to the door tells me he understands.
If I ask Rassilon “Do you want a chooky foot”? (chickens foot), he runs to the freezer where they are kept, so not only can dogs understand the words, they can also relate words to items.
That is why (strange as it may seem to non dog owners), I will tell Rassilon I am going out and will be back soon. He understands and goes to bed to wait, then goes crazy when I get home. If I don’t tell him I am going out alone, he will try to get into the car then will not want to go inside. Dogs are SMART.
Regarding #10. The more dogs you have, the harder this becomes. But remembering that the dog will be scared without your presence will hopefully overcome your sadness. Remember, you will be the last thing your dog sees. I left my last dog at the vet to be put to sleep, and I regret that so much when I think of how scared she must have been all alone.