is it possible to check your baggage for the next flight at terminal 7, after you pick it up instead of having to drag it to the next terminal for your connecting domestic flight?

I would try their website or a forum more local to JFK. For baggage concerns you should talk to your airline.

JFK Airport

http://www.jfkiat.com/ (Official site)

http://www.jfkairportguide.com/ (Third party site)

If you arrive at T7, with ANA lets say, and you continue your journey with US Airways for Example, YES you can do that. If you arrive in any Terminal other than T7, you need to pick up your luggage there and drag it over to T7.