In common with all royal weddings - the Crown Heads of Europe and all the royalty across the world get invited. I don't see anything odd about any of it.
He wasn't Dotty, Blair was. I should think a PM has enough to do without taking on that role. So there is another list then for the Middleton's and their guests? Wonder how long that one is.
Ben Fogle is a friend of William and Harry and has been involved with them both on various outward bound type expediitions for quite a time. I am not surprised at his invite in any way.