The only one I didn't get has now been defined for me:
Re #4: a Hail Mary Pass is taken from American football - it's a long shot in a desperate attempt to redeem what looks like a hopeless situation. John McCain's appointment of Sarah Palin as his no. 2 was called a Hail Mary pass. So in publishing terms, that would be like Anita Brookner writing a book with a car chase and lots of sex.