Curious, have you ever talked to a physical therapist? I've learned a lot of the maladies people live with are correctable, even sometimes things that seem permanent. Many running overuse injuries, for example, boil down to muscle weakness, muscle imbalance, or bad posture.

Without seeing a therapist, try doing this every day or every few days to elongate your 'posterior chain' and help your posture reset (which will help your knees, ankles, elbows operate under less duress): https://www.youtube.com/watch?v=4BOTvaRaDjI

Why would you blow all your salary? On something that is uncertain to work?

As a DIYer for 8 years 'ish, mudding drywall is an art. Where it might take me 4 or 5 (or 6) to get a good finish on joints or corners, it might take a pro 1 or 2 coats and very minimal if not none sanding in between. Primer and 2 coats of paint won't fill in imperfections greater then an 1/16th in diameter so if you have a lot of imperfections, you'll see it in the finished product.

Let's not even discuss mudding ceilings. The amount of upper body strength needed is amazing, let alone good balance on a ladder.

What do life/health/disability insurance companies think? They might charge higher prices to people in more dangerous professions, and they have big incentives to get it right.

So true, also earning is relational, if you are in a group of high paid folks, you tend to feel you earn less, not matter how much you earn more than average income.

On a relational note to the exercise portion, the max a high earning person often dream (and afford) about is spending a week in a beach 'hut' on a 'remote' island while there are several penniless people who just live on a beach hut for 365 days often without experiencing half the stress.