Don't get unduly bogged down with the example: It works equally well with "horse trainer" or whatever. Clearly some professions have a bearing on your risk profile with regard to certain types of insurance, and there is not always a clear distinction between risks you incur as a private person and risks that your business needs to indemnify you against. -- Like, if you're in a job that involves a lot of travelling and being away from your family for extended periods of time puts you at greater risk of developing mental health conditions etc.

I think the numbers may not come out the way you think they will. Sedentary lifestyles are by far the largest medical expense in the country as a whole, so office jobs I would expect to have much higher premiums.

Sure you're not gonna get your sternum crushed by a falling 2000lb pallet - but those situations are already typical covered by workmans comp and other company insurance.

That's not really true like you think, though.

They simply have different health risks than you. It is a deep hole here - should an employer be penalized for a bad work environment (stress, working long hours, lack of sick leave, and so on) that many office workers face? After all, these things lead to more sickness and a greater chance of mental health issues.

How do you figure the risk of accident for the roofer compared to the risk of obesity, carpal tunnel, and back issues tied to a nice office job? Does your risk of injury while jogging for exercise increase? How about that increase in detrimental health effects from the commute? Do you give the roofer bonus points for leading an active lifestyle due to their work? Doesn't an active lifestyle carry its own risks?