1: "Are you trying to tell us that Windsor Castle is not, de facto, in every possible practical sense, the Queen's?"

Yep - Windsor Castle is owned by the The Crown Estate and is an "Official" Residence - it is not the Queen's. The private residences of the Queen are Sandringham and Balmoral both bought not stolen.

2: "I think I'll invent a quango, sign over the ownership of my house to it and make it responsible for decorating it, maintaining the fabric, doing the garden, restoring the run-down bits, rebuilding it in the event of fire (because I won't be insuring it, of course) and, not least, looking after my artwork (a twenty-quid bust of Beethoven in my case)."

Please do, won't do you any good of course as no-one would put any money into it, so you would end up bearing all the costs yourself and on your death, because you have signed it away, the property would revert to???? The Crown Estate.

3: Finally semi-right about something - the Queen did not pay for the repairs and restoration of Windsor Castle after the fire she merely chipped in £2million towards the costs. Opening up Buckingham Palace and Windsor Castle to the public and charging an entrance fee paid for the rest.