I used to take some flack when I would paint a stripper, red or green. Thanks for taking the pressure off, lol. I do like it quite a lot, it certainly is unique, I can honestly say I have never seen a canoe like it.
I'm not sure what you mean... The way I broke it, I put the glass toward the floor, put one end on a block & jumped up and down until it broke. I thought it would be most likely to pull away from the wood by bending in that direction. You think it would have been more prone to separation if bent to failure with the fiberglass layer up? (actually, I guess that's how a rock would bend it)
Your test panel was tested under tension, which is where fiberglass is the strongest. The results may or may not have been different if you'd flipped it so the fiberglass was under compression.
A rock would place the hull under both compression (outside of hull) and tension (inside of hull) since it's laminated on both sides (much stronger than your test panel).
If this hull was for running whitewater I might be concerned but for what this hull is likely to face I think it will endure just fine.