I'll gladly take anyone's 2 or more cents they are willing to share about how to maintain and operate these wood and canvas canoes.
You have an unusual, attractive canoe, and with proper care you will enjoy it for many years. Here are some thoughts about some of the issues you raise:
Some links to some discussions in these forums about using a canoe with old, cracked, and peeling paint –
http://forums.wcha.org/showthread.php?t=5790 see pp. 2-3 of this thread
http://forums.wcha.org/showthread.php?7769-Painting-over-existing-paint&p=41339#post41339
http://forums.wcha.org/showthread.php?5933-quot-Minor-quot-Restoration-advice-please&p=32358#post32358
http://forums.wcha.org/showthread.php?7775-Temp-repair-to-bare-spot-on-canvas&p=41357#post41357
http://forums.wcha.org/showthread.php?7619-time-is-not-on-my-side!&p=40689#post40689
http://forums.wcha.org/showthread.php?8564-Smoothing-Canvas/page2 starting at post 12, on bondo spot putty
http://forums.wcha.org/showthread.php?6607-sanding-or-not&p=35286#post35286
http://forums.wcha.org/showthread.php?8906-Repaint-Tips
Before you paddle the North Carolina sounds or any other salt water, you should take a look at the discussions at:
http://www.wcha.org/forums/index.php?threads/need-advice-restoring-my-1927-otca.18393/#post-95727
http://www.wcha.org/forums/index.php?threads/1968-old-town-lightweight-restoration.17718/#post-91699
If I were to use a wood-canvas canoe in salt water, I would wet it down thoroughly with fresh water before use – so fresh water gets into the wood around tack heads, cracked paint and filler, and other spots where wood might not be sealed, and would rinse it out thoroughly afterwards with fresh water. A couple of day trips would likely do no real harm, but salt water harm to canoes is not reversible.
Q. What’s the best canoe to use in salt water? A. Someone else’s.
I would borrow or rent a fiberglass, royalex, or other non-wood canoe and leave my wood-canvas boat at home.
Pulling a canoe onto a beach or river bank is fine, at worst should cause no more harm than some scuffed or scraped paint that is easily touched up. Stepping into or loading a canoe on a bank or beach is not so fine. Generally, your canoe should be afloat when entering it and when loading anything much heavier and harder than a soft day pack or a couple of spare paddles. The stress to the hull of a heavy point load (the foot of an adult, the edged of a cooler or wanigan that slips from your hands) is spread widely by a hull structure supported by water, but may damage an unsupported hull where the point load may crack a rib or plank – likely the cause of the damage to the ribs in front of the aft seat in your canoe.
For the gentle use you propose, if you are carrying nothing more than a picnic lunch on a day trip, the cracked ribs shown in the photos of your post that has your planking sketch would not worry me too much if the canoe is used gently and carefully. They don’t appear to deform the hull.
But -- the cracked ribs shown in your first series of photos, where the cracked ribs appear to be just forward of the rear seat, are more problematic, because the ribs are visibly misshapen at the points of the cracks deforming the hull. The planking and the canvas outside of those cracks have been, and continue to be, stressed. If you do paddle with these broken ribs, you should use the seat and not kneel when paddling, keeping your weight off the cracked ribs – certainly off the cracks themselves. I would also place a mat of some sort (something like that at
https://www.harborfreight.com/anti-fatigue-roll-mat-61241.html, cut to size) in the area where your feet would rest and where you would have to step when boarding and reaching the aft seat.
My 2¢ -- I’m sure others will be chiming in.
Greg