Does a private pilot taking his friends up for a free flight mean that those friends know the risks more than the same friends paying for it?
Not at all, but those who frequent flying clubs are probably going to have more idea than those who select a flight on a website. If they pay for it, its public transport and then you pay for a higher level of risk management (Protectionism). Not to be confused with cost sharing but will the average friend understand the difference.
Genghis has it right.
Oh..what I meant was with the risk of being sued by friends.
If you are dead and they are dead, their relatives may see your estate as a big red apple.