4) why is still considered that 65 is the magic figure of old age, I aam a baby boomer, and 65 is no longer old age for most. We could redefine old age by starting retirement at 68 or even 70, we'd still be living longer and in better health in retirement than our parents and grandparents. and bingo, problem solved. Vs 2 million more immigrants in perpetuity. I continued working as a GP until the age of 72 years, almost 50 years as a practicing physician.

It's not John. It's 66 soon to rise to 67.
of course that's all about the government saving money by not paying any pensions till as late as possible in the hope you die first.

On exactly who dies, a practicing physician as I'm sure you know, doesn't suffer from the same physical wear and tear as a labourer or metal worker: as a consequence health professionals such as yourself have a much lower mortality rate ( in fact the best) and live quite a bit longer. The
Best way to deal with retirement age would be to have some kind of sliding scale from highest mortality to lowest so at least some worn out working class people get to actually retire and doctors such as yourself don't die of retirement boredom...