I like your idea framing the quotes as an alternate telling. They were listed first out of habit (ex-philosophy major), but you're right that this is primarily our story to tell.
Empathy
The difference between front-stabbing and giving good feedback is one of maturity. If you've had many conversations with young kids, they are incredible at giving blunt feedback, but it's only funny because they are tiny humans. Some of what they say would be unconstructive coming from an adult.
Front-stabbing, to me, is someone trying to justify being an asshole. Your comment is a great example of the difference, of being honest and direct but mature. The opposite of the kumbaya culture isn't telling someone they suck, even if you do it because you want them to be better.
Don't always be right
This is my fault, I mixed too many concepts. This value is about not getting complacent with success or being afraid of failure. I don't want us to get it right every time, because experimentation (where the magic happens) involves making mistakes. As you point out, that failure isn't the same as taking the right risks. This value is counteracting our need to be perfect, about pushing back if we seem to always be getting what we expected.
Happy to dive deeper if I didn't answer your questions. Thank you for the thoughtful consideration!