Another factor affecting your progress on the ICW is how you time your arrival at anchorages. Ideally, you'd leave one right before sunrise when there is already enough light, and you drop anchor right before sunset. In reality, there can be quite a few miles between successive anchorages. On day I misjudged and ended up having to anchor in Albermarle Sound, where it can get pretty choppy. Not a fun night. Definitely get Skipper Bob's Guide to Anchorages!
I'd avoid Cape Hatteras altogether, especially in a boat that is new to you and with shorthanded crew. And in terms of actual miles the cut through the ICW is shorter. And the inlets around there are not that good in certain weather conditions (i.e. wind blowing against outflowing tide). Read this as a cautionary tale: Survivors of March 6 shipwreck say they stand by the choices they made. - Baltimore Sun
After Beaufort, NC I'd try to sail outside as much as possible, given a good weather window, maybe for a day, through the night and get to a harbor the following day way before sunset. Get weather updates regularly through VHF or your smart phone when you are close to shore.
Make a list of the good and bad inlets along your route so you know your escape route if things turn nasty. Some are navigable in all conditions, while with others it depends on current conditions. Always be aware of the tide and the effect it has on inlets. The book above has a good explanation of these factors.
If you sail at night, I found my AIS receiver (Standard Horizon Matrix GX2150 integrated with VHF) a great help and comfort, as you'll see a lot of big ships and sometimes it is hard to tell what direction they are going, especially the cruise ships. With AIS these mysteries disappear.
This will be a fun trip!