What I didn't see mentioned in this post: probability of death by car crash given no interventions, cost (mostly in time) of performing each intervention, and amount it decreases your death probability by. It seems like most of the interventions outlined above are pretty high-cost ways of avoiding an already low risk. Do the proposed strategies actually increase the number of quality-adjusted years of life?

Also note that health-related risks (cancer, heart disease, etc.) are probably all grouped separately but going to a doctor regularly helps with all of them simultaneously. I realize that these are unlikely to affect 25-year-olds but behavior in your 20s can affect what happens in your 40s and 50s. (EDIT: I reread the post and saw that you did mention eating better.)