Lots to digest, but initial points that jump out at me are:
We will not accept promises of support from third parties
and
although there's reference to people ...... whose sponsor is in receipt of any of the following disability-related benefits will be exempt from the financial requirement in respect of that application stage there's no direct reference to the status of pensioners.
It seems that the only way they can apply is if the pensioner has savings (ie shares, bonds etc) .......where the sponsor and applicant have no income which may be counted towards the financial requirement, £62,500 in cash savings will be required for the financial requirement to be met at the entry clearance/leave to remain stage