Paul, Shinnecock Inlet can be a killer. The bottom changes rapidly and when the wind and water run contrary, it can look like a washing machine is running. Even the USCG boats turn back and won't run it in really bad weather.
Unless you have plenty of daylight and smooth conditions, I'd suggest passing on it and staying offshore. The south shore can be a beautiful night passage. But all the inlets (even Jones and Fire Island) can get real nasty real fast, you need to stay on top of conditions and *always* plan for the option of simply not entering the inlet if they are not good. Especially if you have engine trouble.
If you do go in, especially FI inlet or Jones, brings GOBS OF BUG REPELLANT. They'll fly a mile for a meal, and they bring ALL their friends.