Replying to Risk Analysis / Acceptable Risk Levels

I know this is very subjective and many of you probably haven't personally evaluated it or though much about it before.

What defines your acceptable risk vs. reward when it comes to life in general? How much risk is to much? What factors do you consider when risking an activity or line? Do you consider life expectancy vs current age? Degree of pleasure, length of pleasure, impact on others, potential consequences to yourself and others?

I ask because I just purchased a speed wing ($2500) without really considering the full risk vs. reward and am having second thoughts about getting into both speedflying and speedriding. When I started back country skiing I knew I could mitigate risk, and the rewards were well worth the minimal risks I would be / am taking. Driving is a very commonly accepted risk, despite the 1% lifetime odds of dying in a car accident. Why is it so acceptable? Obviously because the time it saves and the convenience far outweigh the risk. Would people still drive if the lifetime risk of dying was 10%?

Time is so precious, is it worth taking extra unnecessary risk to increase our pleasure in the limited amount of time we have? People know smoking and drinking take years of their life, yet still engage in these behaviors... why?

I hope to keep this new activity from my family and close friends. I am currently writing a letter to my family explaining my decision, my acknowledgement of the risks etc... in the unfortunate circumstance that I find myself dead.

Sparksnotes:

What do you consider an acceptable level of risk?