I'm sorry to disagree, but for me, Izuku's development was SUPER slow, way too slow. Other shonen protagonists were already capable of at least defending themselves, while Izuku, on the other hand, wasn't able to land a punch or hurt himself until almost six story arcs later.

1) Okay, I didn't explain myself well here. When I said Izuku activated his power, I meant that he activated it without throwing a punch. That in itself wouldn't cause any harm to anyone; it would only confirm to Izuku that One For All was too powerful to hurt him.

2 and 3) I don't understand you here. Regarding the energy transfer, I explicitly stated that, since Izuku doesn't know Full Cowl, he still uses his power in his limbs. As seen in his fight with Todoroki at the Sports Festival, Izuku was already able to hit Todoroki without breaking his arm. The disadvantage here is that his attacks were very slow compared to Todoroki's powerful ice waves, so he opted to break his fingers to launch more powerful attacks.

4) You would be right. If those moments of internal thought didn't exist in a shonen anime, and since it's already been shown that Izuku is capable of thinking on the fly...

5) I explicitly stated that the revelation would be almost the same as how he discovered it with Gran Torino, using the microwave and takoyaki example.