I've learned that the first weekend of every month is always "special event" pricing at the Brooklyn museum. How bad did you need that charge if you came back several times that day? If you could wait, wait until the museum is closed on sunday (which I think is 6pm) and the rates go back to normal. The other option is the Urban charger in the William Vale in Williamsburg. A good piece of advice is learn where the Destination chargers and L2 chargers are if you don't have at home charging. Plugshare will help a lot.
On the charging for parking front, I don't mind $5 for an hour for non-highway superchargers (free in malls with validation). It keeps people from abusing free supercharging, it makes people charge efficiently and leave when charging is done.
NYC is the most transit dependent city in the US. NYC is also physically one of the largest cities in the US as well. Our longest subway is 34 miles long and it DOESN'T even go from one end of the city to another. No other place in the world can you travel over 40 miles for $2.75. Traveling to Manhattan is easy, traveling from Manhattan is easy. Traveling from any other borough to any other borough is not.