There is no nice tidy time, they get worse the longer you keep them in the freezer.
Depends. Deep frozen, we had one for just shy of a year and it was
fine. OTOH, I've had skinless chicken develop freezer burn in four
months.
I've had 'em for years. Especially if your freezer is really cold. I
recently cooked a leg of lamb that was probably 10 years old, and it
was fine. Fish, too, if it was packed in one of those packages with
all the air sucked out.
Stuff that's loose in bags (like chicken parts) freezer burns much
faster. It's still edible (for certain values of edible) but best in
stews etc. where it isn't the principal ingredient.
Hm.. must remember to clean out freezer.
Dave