Re: North from Charleston
I just did a similar trip this past year, also in April. We went ICW from Charleston (left nice and early from Patriot's Point around 0530) and up to Georgetown in one day. We enjoyed two days there before we left up to Little River (Myrtle Beach) - also took a day of motoring.
We went outside at Myrtle Beach, and cut through Frying Pan Shoals through the 12NM Frying Pan Shoals Slue - no issues there, its well marked - and kept on through the night to Morehead City in the morning. We watched beautiful thunderstorms track out to sea while we stayed nice and dry. After a few days there, we kept on going.
I'd recommend going outside as much as possible - the ICW wasn't the most entertaining part of the trip, especially since a sailboat is just a slow powerboat then. There were a few places heading up to Georgetown and on the Waccamaw River where we were able to use our jib to motorsail for a little bit.
I don't recommend heading around Cape Hatteras without knowing your level of experience. Going around NC on the outside can become dangerous quick - the type of storm that would drive you inside on short notice will close all of the inlets anyway.
1981 O H Rodgers 33
"The cure for anything is salt water - sweat, tears or the sea."
- Isak Dinesen