G-EMMA
You've nailed it there. It's either Freakonomics or the Undercover Economist, I forget which, but in one of those books exactly that statistical analysis is done.
And the answer is predictable - in terms of hours doing the activity, flying is more risky than driving, because people spend less time flying than virtually any other activity. Even passenger flying on a big jet is more risky than driving. I'm not sure how the probabilities are skewed for private pilots but I'll dig out the books tonight and have a look.
I often think 'I could die whilst doing this', or, 'get it right or there's a risk you'll be dead'. I actually think it helps focus on getting things right, as I'm convinced even as a stude that everything I've been taught is for a reason and therefore doing it reduces the likelihood of death or serious injury.
I secretly think the risk is one of the reasons I do it... Interestingly, every non pilot I've spoken to thinks it's more risky than it is...
Stick & Rudder makes a case for tailwheels being more difficult to fly than tricycles. Whether or not that converts into risk or any difficulty is netted out by the additional training required is up to your individual perception of risk.