YES to all of the above. Ann Arbor has a ton of great food to offer. Middle Eastern (Jerusalem Garden, Sheesh, Pita Kabob), Indian (Raja Rani), Ethiopian (The Blue Nile), Sushi (Sadako, Sushi.com), Pizza (Pizza House, Cottage Inn), and pretty much everything in between. If your boyfriend likes hole-in-the-wall type places, Ashley's is a great one. It's right on campus, and they have good food and a crazy beer selection.
The areas closer to campus are definitely more dominated by undergrads (around South university and State Street). Main Street area is only a few blocks away, and it's an older crowd (in a good way, haha). Tons of great restaurants and bars, as well as music venues (The Ark, The Blind Pig, Live at PJ's).
The Arb is a huge park right on campus, it's great to hang out there in the warmer months. I think you'd really enjoy it here, let me know if you have other questions!