Yeah, I'm the artistic type and I spend more hours in COD's Emblem Designer than I do in the game (mostly because the game just sucks now). I would pay a flat fee for the right to use my custom artwork in ED, but not for every time I changed my paint, because that'd stifle my creativity (and my obsessive improvements).
Yeah, kids will paint knobs (or, more likely, that shot of the chick's a** that every third COD player has as their logo) but how many of them will PAY a fee to do it? Not many, is my guess.
Imagine this: you can create paint jobs, and then list them for sale in a marketplace. If another player buys it, Frontier gets 100% of the cash, you get a nice in game credit bonus.
Oh, and get paint jobs into the XBOX ONE edition, stat! (Please)