If it’s affoardable, I would recommend living on campus the first year because that can be such a great way to make connections to classmates early on, make friends, and build your community. But I do still know plenty of commuter students. It just takes some more initiative to get involved in clubs to build a network of friends. It is very common for students on co-op in the area to commute for those 6 months, though. In terms of financial aid, I believe that Northeastern promises to never reduce the university need-based aid (http://www.northeastern.edu/financialaid/grants-scholarships/promise.html). I don’t know how this plays out in reality, but that might be some assurance.
For the AP issue, you can count up to 32 credits. But you can still use the AP to place out of intro-level courses beyond the 32 credits, though. This definitely could make it possible to graduate in 3 years, depending on the major and what those AP classes are in. (In some cases, it’s not recommended to skip out of intro classes using AP, depending on your major, the course, and the student’s confidence level in the material.) This was my original plan, since I came in with 45 credits (back before they set a cap): 3 years, maybe 3.5 if I did a co-op. I ended up staying for 5 years and 3 co-ops. So keep an open mind, too!