They're perfectly safe to fly, but not very safe to crash.
Hahahahaha that's so true!
Danger level mostly depends on the pilot.
I used to be really into planes and want to fly, but the dream sorta died as I grew up.
If you aren't paying attention, then you're pretty much no better than a drunk driver.. and a major risk to yourself and anybody else potentially around you.
Thunderstorms can be dangerous, I believe the rule of thumb is to stay 20+ miles away.
Don't overload the plane!!!
Don't be cocky!!!
If you're having any issues with your inner ear, don't take the plane out!!!!!!!!!!!!!! Yes, you should be able to trust in your instruments, BUT ... don't take extra stupid risks!
Never overestimate your skills.
Assuming you are responsible, and practice what you learned in class, flying is actually very safe, even in a small single engine plane.