Flash,
Your understanding is very good. The only things I would add are that you need to add to the figure of twenty times your final salary pension, the tax free cash and that any pension benefits taken pre 2006 are calculated as twenty five times, and not twenty. If the LTA drops, then it starts getting serious for a lot more people. Transferring deferred benefits is banned in about 5 weeks, new guidance allows you to leave your private pension to absolutely whoever you want, free of tax. Not so with an unfounded FS public sector pension though.
Since August 2011, if you exceed your annual allowance (£40k) and incur a tax charge of under £2000 then 'Scheme pays' rules apply (search: Annual Allowance Scheme Pays August 2011 etc). It's tosh of course, you pay because you get a smaller pension later on. Anything more than a £2000 tax charge, then you stump up via self assessment. The annual calculation is more complicated and revolves around a multiplication figure of sixteen, cash, start and finish date salaries of a few years and the inflation rates for September.
I hadn't heard that about the Parliamentary Contribution Pension Fund. I shall rummage around. If so, another appalling aspect. Various aspects of The Judiciary Pension Fund though? Well.. no comment!!! Ed Moribund has suggested though, he will allow using four years unused allowance, and not as it is currently, three. Steve Webb, the pensions minister, wants to scrap the lifetime allowance completely. It's almost worth arranging to get divorced, take a Benefit Crystalisation Event hit reduction, and then getting back together with your ex in time for a few more years accruals. But they might take the money and then run off with your best mate. Which would be doubly annoying.