*sigh*

Fans obsess more about these details than GL does ... ;)

Anyway... The Emperor being 85 in SOTE seems to be about right, if we start counting from Ian McDiarmid's real age in TPM (age 55), add 10 years until the Clone Wars, and then 20 to the OT. Although, I think there are also a couple of them between ANH and SOTE.

I would think that using the Dark Side of the Force also speeds up aging for both The Emperor and Darth Vader.

As to the general citizens: There are many races, living in many environments. Not all of them are living on Chandrila or Alderaan with it's low, wealthy population and clean air. Many are living lives full of stress, drugs, pollution with an unhealthy diet and lack of exercise like humans on Earth in the real world.