"You live in Boston."
You can eliminate the plural "Bostons" for a city (unless you write science fiction books with alternative dimensions).
As the verb is "habitas", it's impossible to have a genitive here: there is no noun.
Of boston for who?
Same :"for Boston" with "to live"? To live for Boston? I have no idea how to say this in Latin (someone will tell us), but, as you have "habitare" you wait for a place, and often a locative (if it's a city) or an ablative with a preposition (if it's a country).