Haven't read all the posts, but my (jumbled) thoughts:
I ran around in the sun in the 70s, didn't wear sunscreen and burned.
I've had malignant melanoma. Luckily caught in time, but still have to be totally protected now, with 6mthly checks. All that 70s running around will just start to catch up with our generation now.
My friend also ran around in the sun in the 70s, etc etc
She had malignant melanoma too. She's dead now. She left behind 3 very young children.
The ozone is thinner over much of the UK than in some of the hottest parts of Asia/Australia. I spent 3yrs in Australia & Asia and didn't burn (pre skin cancer), came back to the UK and burned in an hour in the Lake District.
There isn't that much difference btw SPF 15 and SPF 60 (93% protection from UVB vs 96% protection from UVB)
Cheap sunscreens eg Tesco are just as effective as rip-off expensive brands.
Some of the once-a-day products (esp P20) don't offer enough UVA protection - UVA rays are just as dangerous. So you have to look for a 4 star UVA protection minimum.
The only reason some health professionals are starting to query sunscreen use is that it is being used to prolong time spent in the sun - as a security blanket. Nothing offers complete protection.
I would never let my kids out in the sun without sunscreen. I put some on DD before she goes to preschool - I'm also writing to request that more will be applied when she's out on an all-day school trip next week. Will be interested to see what they say - they have SunSmart posters all over the school, they'd better not refuse...