Fracture of R humerus in 4 month old puppy

Question
Our Golden Retriever puppy fractured his right humerus - the head of the bone - jumping across a creek while we were out hunting (we had let him come along just for the fun and experience, and a chance to watch his older housemate at work).  He is having the bone pinned tomorrow morning at 9 AM.  Our vet, who isn't doing the surgery, but is scrubbing in, says we will have to keep him shut up in a kennel or a very small room (we will probably use our bathroom) for 4 weeks.  At 6 weeks, if all goes well, they will remove the pins.  I'm worried about several issues:
1) How do we keep him from getting bored and frantic during the long period of confinement?  We had thought of getting a child's playpen to put in our living room so he wouldn't feel too left out of the family, but our vet vetoed that idea as she is afraid he would jump up onto the walls of it.  I can't spend my life in the bathroom with him, but I'm afraid he will feel shut out and bored to tears!  
2) How do we get him back on track on his housebreaking program - he has been on morphine and in a pen at the vet's for the last two days, while awaiting surgery,  so of course he is just going in the kennel.  At what point in his recovery will it be reasonable to try to get him to let us know that he needs to go out?
3) This pup has been walking with us on our daily walks since he was 11 weeks old.  We started out with 1 mile, and he was easily doing 3.5 to 4 miles and enjoying it immensely by the time he was injured.  Now I wonder if we strained his little bones some how by exercising him too much?  Is that possible?
4)  One of the reasons we are putting him through all this is he is a wonderful, wonderful dog - great temperment, obviously very intelligent and wonderful hunting instincts - shall we keep him away from the hunting situation until next season or would it be feasible to take him with us walking through fields in late December, perhaps on a leash?  He has been so excited about the birds and we hate to squelch that interest - our season ends in early January and the bird chasing opportunities will pretty much be over.
5)  Can dogs get bedsores or skin breakdown like people do from being in one position?  He is laying only on his left side, and we have noticed he really seems to enjoy getting the left side massaged during the two visits per day we are allowed with him while he is a patient at the vet clinic.  Anything special we can do to help with this?
6)  One of the possible outcomes we have discussed with the vet is the idea that the growth plate on the side of his elbow may close prematurely.  Our vet recommends neutering dogs at a fairly young age (5 months or so) but wouldn't we want to defer that surgery in hopes of letting the testosterone close the growth plates of his other bones?  
7)  Any other suggestions for rehab of an injury like this?  We respect our vet and trust her expertise, including the fact that she immediately declined to operate on him, stating that he had to have an orthopedic specialist do this repair.  But we live in a small town in Montana and second opinions are few and far between.

I apologize in advance for the length and perhaps the irrelevance of these questions.  We love this little dog and have great hopes for him to be a family member and hunting companion for us for many years and we are just worried sick.  Thanks for any thoughts or advice you can offer us!  Kathy  

Answer
Put him in a dog crate and put that in the living room.

Buy lots of toys.  KONG TOYS are the best because you can STUFF them with peanut butter and cream cheese and that will help keep him busy.

He will still be able to have some activity as in going out on a leash to the bathroom....you should still try to take him out every 2 hours to keep up on the house training.  His leg should be bandaged and the bandage will have to stay clean and dry.

Fractures happen in puppies if they fall the wrong way because their growth plates are weaker.  It is nothing that you did wrong.  Dogs need exercise...he just landed wrong.

You will have to follow your vet's advise as far as when he can go on walks, etc.  Pups do heal quicker than adults.  I would estimate that 2 weeks after the pins are removed, he could start doing light exercise.

He should not really get bedsores because he won't be laying down 24/7.  He will be standing and sitting in the crate.  If he does prefer to lay on one side more than the other, you can roll him over.  Best bet is to provide A LOT of padding in the cage.

Having him neutered is not going to affect his growth plates closing.  Growth plates in large-breed dogs do not close until about 1.5 to 2 years of age.  You certainly don't have to neuter him right at 5 months of age, but I wouldn't wait too long or some undesireable behaviors may develop.  

As far as rehab (and outcome), you should ask the orthopedic specialist because s/he will have the most experience with recovery and rehab and post-op instructions and care.

Good luck.