What you should pay most attention to (except for Cape May where you will have to deal with shoaling and will have to pay attention to depths) is currents. Go to Tidal Current Tables
for predictions for the C&D Canal, Delaware River, etc. You'll want to ride the currents in the direction you're going for as long as possible. I have to get going now so I can't do your timing for you, but I'm fairly confident someone else will be able to help. It's an interesting run - just make sure that the current and wind are not opposing when you go down the Delaware, or you're in for a rocky ride. As you mentioned, there is very little that has not been discussed about your particular trip if you do a search for "Cape May", "C&D Canal", "Delaware", etc. We did it a year ago May and it was somewhere between rough and enjoyable.