Hundreds of thousands of people have done it to blend in, in the US of A. I ran into a lady named Pack several years ago. We thought we could 5th or 6th cousins. Turns out her great great grandfather changed the Czech "Pacek" (the "c" had a tail) to the English "Pack" in 1910.

We don't know your old friends, so we can't answer your last question.

You have to be 18 or over, and it can cost as much as $400, depending on the state.

Neither "O'Brian" nor "O'Connor" is unique. Both are very common.

Both will give you fits, too, as you'll be recorded as
Obrian (no space)
O Brian (space)
O'Brian (apostrophe, no space)
O' Brian (apostrophe AND space)
plus all the above with the "Brian" part spelled "Brien".

Repeat for O'Conner and O'Connor.

He is
your great grandparent's first cousin
your grandparent's first cousin once removed
your parent's first cousin twice removed
your first cousin thrice removed.

No one will understand you if you say "thrice", (I have used it eight times in spoken conversation in the last 50 years, and each time people looked puzzled) so use "three times" instead; first cousin three times removed. You can abbreviate it 1C3R.

"from" is a completely vague and useless word in this case. The answer would be that she lived in multiple places. That is the fact. She is not "from" any of them, more than the other. If someone asks where she was BORN, she can give a correct answer to that. it is specific, it is not where she is "from". Why do you assume that all persons are only "from" a single location? Or that all persons "grew up" in single locations? She "grew up" in several places.
Normally persons have one single citizenship, which is their birth place.. but that is NOT all persons. A good example is persons who have military parents (which is what this clearly sounds like). I do not know of anyone with 3 valid citizenships. Two, yes.. NOT three.
Last.. the last name of the father is completely not relevant, and proves nothing at all. You might be the person who says the name is Dutch and German, which is invalid in itself. Many names come from more than one place (just as people do). Her father has German ancestors ONLY IF SHE DOES RESEARCH and finds that they came from there. The fact that she does not know.. only means, no one has bothered to do the investigation. And.. then, of course, she is forgetting that all persons have many ancestors.
The NUMBER ONE PROBLEM in all of this.. is bad assumptions, that persons and names are limited to single origins or boxes. Life is not like that.

Maybe. Only research will tell.

It is physically possible to be 1/64th of something and 63/64ths of other things, but have the surname of that 1/64th guy; he would be your 4th great grandfather, your father's father's father's father's father's father.

And, it's physically possible to move to Germany from somewhere in 1805 and change your French/English/Dutch/Italian . . . surname from whatever "Miller" is in those languages, to "Mueller", which is how you say "Miller" in German, and then you and your descendants spend the rest of their lives putting little dots above vowels.

> I truly love Germany and I think that would be awesome...
That's pretty much the way I feel about having the ability to fly, like Superman, but just for short distances. 200 yards, on a windy day, with my friends watching, would make me so happy my heels would beat on the floor in ecstasy.