1-John loves his brother in Germany.
2-John loves his brother who is in Germany.
Do these mean that John has more than one brother and he loves the one who is in Germany?
3-John loves his brother, in Germany.
Is this sentence correct? Isn't 'in Germany' dangling?
If you don't mind, there are some errors here.
In the UK, I believe it's has just got -- though I struggle with the UK "get".
In any case, your brother is 3rd person singular, and requires "has."
... France, the home of the Eiffel Tower.
... France, where the Eiffel Tower is.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.