1) I've had my dog stand several times. If it's really cold, I try not to do it, but she doesn't seem to get cold anyway. I've also used a boat, I've tied her to trees a ways off, and I've used the bottom half of my climbing tree stand as a platform. To me, the only real concern is if the dog can't touch. I don't think a dog could take that.
2) I hunt quite a bit more, but I still do some off-season training. They'll never forget retrieving or hunting, but they will forget field stuff like heeling, holding, etc... I probably drill 5 days a week in the summer, 1 day in the water and 4 in the field. The difference between a good dog and great dog is half genetic and half hunting experience.
3) I did it myself. It takes a great deal of time, but it's rewarding. It wasn't a cost thing, it was a quality thing. Once my dog had the basics I hunted specifically for her. I'd go shoot pigeons, rails, doves, etc. Things I wouldn't hunt on my own, but that provided the needed exposure to real birds and real bird smells. I consider game farms to work for this as well.
4) Not inappropriate at all. Just get your dog out. Labs make surprisingly good house dogs.
