Re: ICW private docks?
Check craigslist. Don't know about NC, but down here in Tampa Bay the local craigslist has ads for private docks almost every day--typically going for 30% to 50% less than commercial marinas.
Since it appears that you intend to live aboard, I should probably also mention that almost every ad I see for private dock space out behind someone's home or condo says "no liveaboards allowed." You may be very hard-pressed to find a private dock where you'll be allowed to live aboard.
Good luck, though.