Well then look at who he addressed his second epistle to: "those who have obtained like precious faith with us". Could "those" be Gentiles. He is addressing them both to different peoples, the first to the Jews of the Disapora and the second to the Gentiles who believe along with the Jews.
Clearly you're not saying the editors of the NEB or the NAB didn't know how 2 Peter begins. And clearly your line of thought is persuasive to you. But to me almost every argument you offer is more implausible than the one before. I'm not denyng it's due to my thick-headedness.
2 Pet 3:1a - "Beloved, this is my second writing to you." But you're saying the first one was NOT to them, but rather 1 Pet to the Jews and 2 Pet to the Gentiles?
We have such different notions of what argument and proof are that I often find myself just shaking my head.