It's foolish to count driving to the train station in CT. Any time the traffic is minimal into NYC, the parking at train stations is also empty. Really everything you cited is fairly naive for getting into and out of the city. Parking is ~$40 a trip unless you can get a street spot (which can be really hard to count on in most neighborhoods).

The optimal path is to drive to a train station close to NYC that has frequent service, park and take the train for the last bit. I used to use the Greenwich train station and it worked well. The same is true from New Jersey, you can park at Metropark or get dropped off in Seacaucus.

Source: I lived in CT for 3 years, lived in Manhattan for the last 5 years, bought a car and keep it in Manhattan for the last 6 months.