Many congratulations on your wedding! I can't speak for all countries, but here is the lowdown (my opinion) from the UK:
1: All: What do you have against iced tea?
A: The UK has something called "Lypton Iced Tea", it is a soft drink from the 1970s and can only be found in the refrigerators of Newsagents. It comes in two flavors, Lemon and Peach. Lypton is the brand, not a technique, it is unclear if the drinks on sale are vintage examples left over from the 1970s.
2: All: Why is your coffee so small?
A: The higher the concentration of caffine the smaller the beverage. An expresso is diddy at something like 150ml but has more caffine than a whole liter of Grande Skinny Machismo or whatever the hell Starbucks and Costa are churning out these days.
3: England: Why do you eat beans with your breakfast?
A: Like bread, Baked Beans in tomato sauce can be used with any meal. In fact, so many beans are eaten it was found the city of Nottingham eats more Beans On Toast than anywhere else in the UK, perhaps even the worlds. I cannot find any links to back this fact up, which makes me sad.
6: Scotland: What's the deal with haggis? Even your own people won't eat it, so why should I feel obligated to?
A: I am not Scottish but my Dad is. On Burnes Night he reads a poem and stabs a Haggis. If it were not for that Robert Burnes poem, I am sure Haggis would have gone the way of the Dodo long ago, but because of Tradition, Haggis endures.
11: All: Kudos for motor vehicle drivers in all 6 countries making pedestrians scatter like cockroaches when the light comes on. Roads are for cars. Thank you for
A: In the UK this comes from out long history of Public Service Announcement ads on TV. Literally anyone within ten feet of a car in those PSA's die gruesome painful bloody deaths. Cars move, pedestrians move.
12: France: I drank some crazy cider maker's apple moonshine at 74% alcohol. My throat still burns. Thanks!
A: Next time try the Absinthe ;)
13: All: I noticed a distinct increase in body mass index as I traveled through the 'french fry belt' (term I coined for all of the countries who claim to have invented french fries). Is this something you have noticed as well? Or could it be the waffles and chocolate also prevalent in these areas?
A: All the thin people were not visible as they were in the Fry factories making fries for the fatties you saw.
15: England: If your money, Scotland's money, and Northern Ireland's money are all the same, why did the wierdo at the laundromat in London refuse to accept Scottish or Irish currency?
A: Although the "United Kingdom" is indeed united, there are a few factors which cause this - Firstly, although the Irish, Welsh, Scottish and English identify as being British, none of them equate that with being Irish if they are Scottish or being Welsh if they are English etc etc. Secondly, the English are only trained in identifying fake English notes and coins. A fake Scottish note could have a picture of Jimmy Krankie on and an English shopkeeper would not know that was not a person who would or would not appear on a Scots note. EDIT - I was not aware the currency would need to be converted, you learn something new every day!
16: All: In a restaurant, why do you pay more for soft drinks and even water some places, than beer or wine? I would be a complete alcoholic if I lived there, simply because I refuse to pay 4 Euros for a glass of water and don't mind paying 3,50 Euros for a glass of beer.
A: As drinking and driving is illegal in the UK, restaurants here know they have a captive victim who is limited to a very small selection. All of that selection is inflated in price to earn as much £ off the sucka as possible, it is a punishment for not booking a taxi, and is known as the Tax on being Responsible.
17: England: Why do people keep getting upset when buses hit bicyclists in London? Isn't this just natural selection?
A: UK Mums make their children change their underpants by saying "If you get hit by a bus, the doctors will see your grubby undies. You don't want that!" Because of this, whenever we hear someone has been hit by a bus, we are assailed by years of our mums telling us if we are hit by a bus we need clean pants on, and no cyclist has clean pants on after they have been hit by a bus... Their mums would be ashamed, thats no way to go.