I'm no longer sure which post is "OP" in this thread, but the problem is definitely deciding which people are and are not disabled. Setting up an adversarial system where you have to prove disability makes the problem worse, not better: people who are only somewhat disabled lose out, while people who are better at faking it get the benefits.

What about those without pensions? Homemakers, minimum wage earners? Is it fair to ask them to pull their own weight past retirement age?

1. Homemakers typically share and then 'inherit' their spouse's pension (if the spouse dies).

2. Even minimum wage earners have retirement contributions deducted through payroll. Not a lot of money, true, but poor people's pensions are slightly subsidized by higher earners (which is fair, IMO).