I really don't think any dog- no matter what breed -can do with just a couple of baths in a year. That can possibly lead to infection. I am not sure though, never having hazarded it so far.
Yes, bathing dogs depends a lot on the type of skin they have and the oil secretion. Too much washing dries the skin, the hair.. But I've had four different breed of dogs over eleven years and I've regularly given them baths around thrice a month with sufficient intervals in between. No problems so far.
Shedding depends on the breed, too. Length doesn't have much to do with it.
I have personally spoken to my vet regarding the anesthesia. It's not too different from human beings. Anesthesia is a necessity doctors at the moment can't do without. There have been instances where an 80-year old recovers from a bypass surgery without a hitch, but a 29ish young man with no history of chronic illness is comatose upon the correct administration of anaesthasia. It is very difficult to predict. Vets generally do not advise anesthetizing very old dogs, but it really depends on the case.
My Alsatian was on pain medications for a month, so I guess I can safely call the restrictions on that a myth.