...would Jesus not have died if he had not been crucified?

If Jesus died around age 30, then his body was past its prime (ie., he was getting old, and the body was wearing out). This would be especially true in his time, since age expectancy was lower than today. Such an aging process points towards death, for the body eventually wears out and fails.

So, if the wages of sin is death, then Jesus must not have been aging after about 18 years of life?