Unfortunately, with most dog training its the handler(s) that actually needs more training than the dog, at least with your first few dogs. Its very easy to undo any training that has been put into a dog by someone else, and I've seen dogs where this has happened, in fact it happens all the time with gundogs.

I think you did a wonderful thing rescuing the litter, but rather than have him pts, if you really don't have the time or resources to put into owning him, I'd consider rehoming him through a rescue organisation.