In Australia the mandatory insurance will cover any third party medical bills. Any insurance to cover more than that (your medical bill, your property or third party property) won't pay you in case of negligence (drunk driving, knowing that the car was road unworthy etc).
If not for charity there's also the possibility of doing something cheap for portfolio fodder. Then again, cheap seems to bring out the wrong type of person you want to work for.
You could also subcontract for someone you know that does web development. They get less work to do, you get experience, you probably still get paid.
Disagree. It's the whole point of the page, so it isn't excessively redundant if you say it more than one way... I'd just put a single column that's a different color (ie, green) for the best day, maybe with an embedded checkmark or some other indicator for the color blind.
1. The URL - would be better if it's a dedicated domain name (e.g. whenshouldigo.com).
2. I agree with the parent about the color coding. It might be more clear if you use a red-green spectrum for each day (e.g. red for the evening, when things might be more busy, and green for the morning, when things might be less busy).