Brian, a few points.
No federal system in the world would advocate one parliament elected by 90% of the population of the country - so an English parliament would be just too powerful compared to the others and make a break-up of the UK even more likely.
Your arguments against PR are just laughable - to have one party - The Tories - ruling with just 35% of English votes is a travesty. It also ignores the very real regional differences - Labour get 40-50% of the vote in the North of England compared to the Tories 20-25% - in the South the percentages are almost reversed. Tory rule over all of England is likely to foster the same resentment in the North of England that led to the Celtic fringes demanding devolution. PR regional government solves the West Lothian problem and gives a voice to all the regions. You also forget that 10% of England has already voted overwhelmingly to have regional government - you conveniently want to overule the democratic choice of Londoners (then there are the dozen or so city mayors in England decided by referendum that you want to overrule).
Finally, PR has not been a disaster in Scotland, Wales etc - a couple of weeks of open negotiation is better than a quick installation of one party dictatorship that most voters opposed. Scotland and Wales have the fastest growing economies and are spending more on public services and also now have a much stronger voice in the Union. Not bad for an electoral system still going through its teething stages. This 'world will end with PR' stuff is absolute rubbish - countries that have had the longest periods of PR elected government have also had the highest growth, best funded public services, lowest inequality, best environmental legislation and highest political engagement. It is our system that is a nightmare that chops and changes policy and undermines any long-term strategy needed to improve the country's infrastructure and business environment. Check out Germany and Scandanavia and tell me their governments are not better than ours.
The spoilt ballot papers in Scotland were mostly in the first-past-the-post section not the PR bit. It was inadvisable to have different electoral systems used for different elections on the same day - the Electoral Commission warned about this - this was an administrative error and nothing to do with PR.