Yeah, I agree with your points, all those events are good material for NadeRin (though I want to note that Nadeshiko's mom and Ena know the story, but they don't go out of their way to tell Nadeshiko, so it's still kept a secret from her). I'm just saying the material is also usable for the sister ship, and it's nice in its own way. As a serial shipper (and an advocate of polyamory), I see no reason why we couldn't have both ships :))
"Both?" "Both!" "Both is good."