(1) what is the sailing like in that area?
(2) does it matter that Camp Lejune is right there, any restrictions?
(3) Is it possible to sail on the ICW, even with lots of tacking back and forth?
(4) what's the weather like end of June?
(5) what else should I be thinking about??
Three days is pushing it down the Chesapeake to Topsail. My dad and I did it in the reverse direction when the weather was nice. It still took us about five days. No, we didn't travel at night, but I wouldn't want to go down that stretch at night anyway. We took The Dismal Canal, which is worth seeing, so that probably delayed us a day.
Not really sure it's worth bringing it all the way down in such a hurried manner since you're passing through some of the best sailing along the way. At Topsail itself, there ain't that much. The inlet can be gnarley, and certainly you can't tack in the ICW. You probably can on The New River.
End of June is very nice down there. There's usually a steady SW wind every day. One possibility is to bring it as far as Morehead City or Beaufort and sail out of there. The drive between Topsail an MC is only about 45 minutes. Or, you could even leave it near New Bern.