1. There will be a Premier Lobby at JFK. Most likely they will have a separate *S/Premier line. Just look for the Star Alliance Silver sign on the signs.
2. There is a Priority Security lane at JFK you can use as well. Just look for the signs and remember that the Priority Security lane can be slower than the regular lane at times.
3. Since UA changed their boarding procedure again. I believe you will board last with the 2P's and will use the blue carpet. Remember you have a bunch of people ahead of you and considering it's an elite heavy segment be prepared to wait for a while..