I hadn’t heard about this. Is his book authorized by Fleming heirs?
Yes, it is published by Ian Fleming Publication. Ian’s actress niece Lucy Fleming owns the rights.
Yes. All the sequels were.
About the setting: Fleming didn't invent countries, so far as I know, but he probably wouldn't have gotten bogged down in the differences between Sierra Leone and Guinea-Bissau.
William Boyd, to judge from stuff he's done that's ended up on television, is always disappointing, and his Bond novel may be a botch as well.