[Zybomb]

I agree with pretty much your entire analysis except for this part.
I think this turn is an autobet for several reasons

1) WE HAVE A FLUSH!!!

lol, but seriously beyond that, I think there's a ton of value to be gained by betting here from Kx, pair and diamond combos and simply one big diamond.

that being said I think his bet was a little too large. He bet about 2 mill into a 3.1 after betting 750k into a 1.6 on the flop. I think on the turn I bet more along the lines of 1.5 - 1.6 to convince lesser hands to continue

I think we're also not giving Moon enough consideration here. You mentioned he's an amateur and yes he is. He is an amateur on the verge of the Nov 9 bubble and has seemingly been playing pretty straight forward and being hit with the deck. I don't think he's going to get out of line with some weird check raise here unless he has a very big hand in the spot that he's in, so we don't really have to worry too much about FPS from him here.

That of course would lead to the last Q.... so if I bet the turn WTF do I do when Im c/red?

We're 6 handed so our hand is enormous obviously....but I did just mention that Moon is unlikely to get out of line in THIS fashion. Like you said 2s arent in his range much if at all and I dunno wtf he could have thats not a flush or better that plays it in this fashion. I assume I'd probably bet/call the turn (convincing myself he has some pair/large diamond combos enough of the time but will shut down the river with these hands since he doesnt want to risk the majority of his large stack when we've showed so much interested unless hes stronger than us) and then fold the river to a shove. My turn bet would've been smaller so the turn c/r would've been smaller also, leaving me with a large stack

Had this hand occurred against an aggressive player unaffected by the final table bubble approaching etc, then it'd change matters IMO

There's obviously nothing wrong with checking behind the turn to induce a bluff on the river (or a lighter call down) but i think we lose value from lots of hands/decline to protect our hand against large diamonds, but yes I think shoving is very bad.