Wee Weasley Welshman,
The issue of what role the oil price has played in the economic downturn is the one point I disagree with you on in your general prognosis. Whilst I agree that the major driver of the downturn in the UK specifically has been the credit crunch and the subsequent housing market crash, the credit crunch itself on a global scale (caused by American mortgage defaults) was caused by the oil price.
What other reason can explain why the first neighbourhoods in American cities to experience housing price falls were the exurbs (where lifestyles have by far the heaviest reliance on cheap fuel), followed by the suburbs? As the crash has played out, these have also been the areas that have been hit the hardest. All this points to the credit crunch being an effect, not the primary cause.
One way to prove or disprove this theory will be to observe how the regional property markets in the US behave once the effects of $50 oil is taken into account. Although it's probably too early to tell yet, since oil price variations historically take 12 months to filter through.
Of course, another factor that led to the housing crunch was the rising interest rate (and irresponsibly-arranged mortgages resetting to unaffordable levels). But the reason base rates were increased was to combat rising inflation - again brought about by the oil price.
Interesting point about the Baltic Dry