I moved to Boston from down South 5 years ago. This thread is extremely entertaining to me.
To those who say Boston has no ghettos, I invite you to take a stroll down Shirley Ave. in Revere, or jump off the Red line at Stab'n Kill stop. Take a drive around Mattapan. It's delusional to not recognize that some of these places are pretty rough. I would agree to the extent that Boston is better than most in this regard, but that's really, in my opinion, because of skyrocketing real estate costs in the city. Folks are trying to rejuvenate bad neighborhoods because they can't afford to do anything else, and still stay in the city.
After reading the thread, I'm not clear on who has, and has not, actually landed here. So, I'll give up my advice.
Don't rent a place in any of the following towns. Mattapan, East Boston, Revere, Lynn, Saugus,.... unless you know damn good and well what part of those places you're headed to. A good for instance is Revere. You can rent a safe and clean, quiet, place in Revere. You can live a block away and get knifed your first time waiting for the bus.
Don't take the chance until you know the place. Rent someplace in Somerville, or Malden, or Cambridge if you can afford it. Look at the Fens, or JP.
Whatever you do, don't look south of Boston. The commute will chew you up and spit you out.
If you like to have a drink, make sure you're within walking distance of the T. That's crucial in Boston.
My two cents.