To read these political satire emails in chronological order (they will make the most sense that way), start with the oldest post "England's letter to take back USA as a colony. (Why would she want us back?)" and read from bottom to top.

To the imperialist British colonizers - That 'z' will have to go to start with
In the light of your indecision over joining a common European Currency - There's no indecision - the answer was NO
You already almost speak our language - It think you have that backwards
Princess Diana will be declared a saint. - Too late
Look up "aluminum" [. . .] we discovered it, we named it, you are mispronouncing it. - Nope Aluminium was discovered in 1808 by Sir Humphrey Davy . (NB: Remember that American film-makers rewrote wartime history so that the US were the codebreakers, not the UK with the Enigma machine.)
"Resistance is futile. Just ask Hawaii [. . .] Norman fops." - Perhaps you should visit Wales, briefly.
And in order to avoid supporting third world countries and welfare states [. . .] Hong Kong immediately. - Once you're done in Wales, you may convalesce in the Falklands. Enjoy your vacation. Wouldn't South Georgia be more appropriate.
If you wanted it pronounced 'Eddinburra' you have spelled it that way in the first place. - Take that up with the Scots - they will demand statehood in their own right or there will be claymores brandished in the Capitol
Scotch characters will wear plaid - Scotch is a drink - that sort of mistake will be painful if you make it in Sauciehall Street
The British film industry . . What British Film Industry?
You will learn your new national anthem "The Star Spangled Banner". - Do you have Gujarati, Hindi and Farsi versions?
It shall be sung every morning at kindergarten, high school, university and your places of work. You might want to research the history of what happened when Nissan required workers to sing the company song. The British working man can be very inventive when it comes to finding Obscene words for such anthems (Note: Brits have already written obscene words to the US anthem)
If it doesn't require 45 pounds of padding, it isn't football. - Well just because its too dangerous for Americans the rest of us don’t have to wimp out
You should also stop playing cricket. Americans can't understand the rules. - Perhaps you might care to wonder why every Peasant in the India subcontinent can figure out something you can't
Any match which takes longer than 90 minutes will be declared a draw. - Right unlike that well known short simple game called Baseball
We will help you to blow up your Houses of Parliament- I've a better idea, lets burn down the White House AGAIN
Roundabouts will be banned. - Better rip up the rotaries in Mass first (Note: the first roundabout in Florida split the population into 2 parts - those who have had a wreck and those who haven't encountered the roundabout yet)
You will also learn the difference between crackers, cookies and biscuits to avoid causing unnecessary confusion to mainland Americans. - We know the difference - you have a lot to learn