Was it purely posture related or did you get an injury on top? One of the things I've noticed is that a lot people (especially those who are into fitness) concentrate more on the front of the body (vs the back) and that tends to exaggerate the hunched over posture of modern work.
Hard to know but I get a well-rounded workout. Could be related to a workout I did where I was carrying 80-100lbs on one shoulder at a time. Could also be 10 flights in 30 days with a heavy carry-on. Years of BJJ, muay thai, karate, multiple rear endings in car accidents. Adds up
Definitely. One of the things I have learned as I've gotten older is that looking after your own health is priceless and has to come before career. Just take it slow and don't be too hard on yourself.