Make sure you are giving your puppy it's food in a puzzle you. Mental stimulation is so much more important than physical exertion. Dogs can go all day long physically, but will tire out quickly if they are mentally engaged. So instead of just walking, do 10 minute training sessions as well. 10 minutes of training is equal to an hour long walk, in terms of "wearing the dog out." Teach you dog "puppy push ups," they are awesome and fun for young dogs! Bones and stuffed kongs are amazing for this as well. Your dog should NEVER eat out of a bowl at this age!
Crates are fine, and honestly the amount you guys are crating is fine too. Just make sure that the time out of the crate is super effective.
I foster puppies and believe me, I don't let the puppies run around the house all day. They get some exercise and outside time, but during the day they are generally in their crate because I have to focus on work and puppies are destructive
Good luck! My dogs are 2 and 4 now and are great at just laying around all day while I work, I hope your dog will become a joy and comfort to you as well!