There are no conditions except for having lived (not worked) in the country for at least 40 years of the 65.
This is basically UBI for elderly and it has been in place since the 1960s.
None of the (theoretical) issues you named have been a problem.
Do some elderly spend all their AOW on a slot machine as soon as it comes in? Sure.
Do some people try to scam elderly because all elderly get AOW? Sure.
But overall the program has resulted in <3% of all elderly living below the poverty line. In other countries without this, such as Germany, you can find older people still having to work well into their 70s to get by.