nutty, you might know all of the following information. I have read some of your messages but not all of them. I've read enough to see you have tried everything you can think of to get a council house in an area you like. I will add my 2ps worth as someone who has not gone through your expereince, but has a little knowledge of council housing practice - but not in your area of the country.
I think the reason your council and HAs tell you a house has been allocated is because it is going to someone who is assessed as being homeless. This is why you are having to wait, even though you are top of the housing list - but perhaps you know this already.
In my area, it's increasingly the fact that empty council properties are going to homeless people. Homeless could mean (and often does) living with friends or relatives or in temporary accommodation. If a person is assessed as being homeless AND with priority need they will be the first to be housed. Priority need means for instance being pregnant, with children, exceptional vulnerabilty or having a severe medical condition. Eviction by family and friends is one of the main causes of homelessness. So if a pregnant woman or a family if evicted in this way, they will get priority.
As more and more people feel that council waiting lists are ineffective, people are less willing to put up with sharing their home with family and friends who are on the waiting list. They are more likely to evict them since their stay will be long term. Also some people (who can blame them) choose to declare themselves homeless stating they risk eviction, rather than wait for years for a home from the council waiting list.
As it stands, about half of homeless households accepted by the council are single parents with dependent children. Many are on low incomes and have no other choice. As I understand it, they will be rehoused ahead of those on the waiting list. As the council in my area is not building more homes, in fact the number of homes is falling due to the right to buy schemes, there are less council homes available. Also, the ones that do become available are often the wrong size: lots of one and two bedded flats when the demand is for three bedded houses.
I know council nominations to housing assocition homes in my area are rising. Housing associations are building new homes too, so this gives hope for those on the waiting list. But as it stands, the prospects for people on the points system getting family sized council homes is not good, unless they wait some years.
I am sure you know lots of this already - but are there any questions this raises? If so I'll do my best to answer.