As for social rents not covering repairs and maintenance of the properties...
...that's not the case in most areas. The exceptions are inner city areas with high rise blocks. System-built 1960s flats are coming to the end of their useful lives. I live and work in an area where the social housing is of traditional brick construction and the picture is quite rosy since the move to self financing in Arpil 2012. Up till then we had more than 40% of our rental income taken away to subsidise other areas.
And in case anyone is wondering - Council Housing is not paid for by Council Tax. Councils that retain housing stock have a separate, ring-fenced account called the Housing REvenue Account.