This
A total oxymoron,he get beat up to protect an unknown kid from flash and them chickens out at the store
Chickens out? Peter didn't seem scared to me, just spiteful. He helps the kid because he's actually a decent human being. He let's the guy steal the money not because he's scared but because he's started a cycle of choices that cause him to shift his actions in a selfish direction.
Yes, he's going through some emotionally difficult discoveries about his father. Yes, he's had a radical life change. Yes, those things are factors in why he's acting this way. But at the end of the day he's acting selfishly. He humiliates Flash, for HIS OWN satisfaction. He forgets Aunt May, because HE put his own interests with Oscorp first. He lets the burglar go, because HE doesn't see why he should help out an a-hole.
Keep in mind (and this is important), Peter was not scared.
He was motivated out of a petty desire to see the clerk get what he deserved. Not so he could teach the man a benevolent lesson in respecting others, but because Peter, Selfishly, kind of liked seeing the guy get what he deserved.
And I probably would have done the same thing in that situation!
The clerk did kind of deserve it, because he was a jerk!
But Peter was still being selfish.
Keep in mind, I'm not saying Peter never did anything evil but he did act selfishly nonetheless, and whether he meant for it to happen or not, Uncle Ben died as a result. And THAT is the lesson.
Peter has Power. Responsibility comes with that Power. To not use it for the benefit of others isn't evil in itself, but it's not the responsible thing to do either. That's what Uncle Ben was trying to teach Peter, and that's the lesson he learned too late.
The lesson is NOT: Don't be a chicken.
The lesson is NOT: Jerks should never be punished.
The lesson IS: If you can do something good to benefit others (the world) you have a responsibility to do that thing, and put others before yourself. Or, "With Great Power Comes responsibility".
Peter put himself first in that situation because he was an angry teenager, not because he was a chicken.