What a wonderful letter. Thanks for sharing this.
I must say, as a small 'L' libertarian with a twisted sense of humor I find this story idea delightful:
"Mmm...Sturgeonish ideas—Well, here's one that might be Campbellish: a society where there are no criminal offences, just civil offences, i.e., there is a price on everything, you can look it up in the catalog and pay the price. You want to shoot your neighbor? Go ahead and shoot the *******. He has a definite economic rating; deposit the money with the local clearing house within 24 hrs.; they will pay the widow. Morality would consist in not trying to get away with anything without paying for it. Good manners would consist in so behaving that no one would be willing to pay your listed price to kill you. Of course if your valuation is low and your manners are crude, your survival probabilities are low, too."
I also loved this: "You could get a Campbell-style story out of doubting the most sacred of sacred cows—except big business, of course; John does not tolerate outright heresy."
And this, as a cat lover (I didn't know Heinlein was a fan of cats!): "What exact knowledge of how human beings work can enable a man always to make other people happier simply by his own presence?
Cats have made a racket and a good thing out of this knowledge for seven thousand years without even bothering to flatter the recipient of the pleasure."