As for Gay Culture, Boston has become highly homogenized. There are a few neighborhood bars (Club Cafe, DBar, Cathedral Station) but the day of the big dance clubs is gone.
I still love my Boston though. Visit the Seaport, Back Bay, South End and Cambridge. Take a day trip (ferry) to Provincetown if you have time. e have several great museums. Chinatown, North End (little Italy). All good.