Questionable Questing

Sure. That scene was quite metal, with Marco fighting until there was nothing left of him but ash.

Kay, what benefits would that give?

A substantial bonus to a Whitebeard Pirates related action of your choice, or a lesser bonus to an unrelated action.

Kay

Would have hoped for an option where he somehow was revived, but in exchange list his Df, and most of his physical prowess(leaving him Paradise notable) though that's probably not an option.

Nah, I figure if I allow that sort of thing it will get silly fast. The largest sort of reality warping I'd allow is for submissions for recruitment, and I'd probably end of rewriting half of those at least.

Ok, so how long you want the Omake to be?

The summary of the battle between Marco and Blackbeard in the quarter 4 rumor mill was roughly ~350 words, depending on how you slice it. So I think its fair to expect a more in depth omake covering the same events to be notably longer than the summary, so something like 500 words at least.

Kay, I'm thinking it will be an Omake as Marco is about to die, reflecting on Teach's betrayal since he's known him the longest, since they were both Cabin boys.

Teach will see eating his powers as 'Always being with him' so Marco gets the idea to spite him and says 'I think I'd rather be with Thatch before blowing himself up.

Should I add an interlude for Marco's df drifting away when no ones looking?

Nah, it respawned somewhere else. And its less that Marco blew himself up and more than he burned himself up. He fought until there was literally nothing left but ash if that makes sense.

Ahh, ok, should he leave Teach any lasting scars?

Yes, but nothing debilitating.

Kay, ideas for a title? Also do you rate on quality, cause I'm at best average at Omakes

I do rate on quality, but my scale tends to go: Unreadable - Bad -Technically Proficient - Inspired, so it shouldn't be too hard.
As for Title ideas: some sort of ashes pun seems the obvious way to go.

Kay

Last questions(for now) what is best case scenario for Whitebeard Recruitment.

And will you add a list of potential Omakes to encourage writing of them?

I'll add an omake list.
And the best case scenario for Whitebeard recruitment would require a nat 100, and would give you a New World Notable (ie: Doffy Executive class) combatant plus some other goodies.

... Would Izo count as a girl?