I wasn't trying to be critical of the recipe or your intentions - I hope it didn't come across that way, but if it did, I apologize. It's just that once you have mashed or partial mashed, the "mystique" of all grain will vanish for you. Even so, there are plenty of great beers made from extracts and there is no shame in making them that way. Steve Ruch who contributes here is one such example, based on space and choice - stellar beers I am told. But a little understanding of the all grain process will help you in many ways. Best of luck with your Oatmeal Stout - one of my favorites!
No offense taken. I have a BS in Chemical Engineering from UC Berkeley and prefer straight to the point comments. I have had good luck with DME and have produced some beers that have been given the thumbs up by some pretty picky beer drinkers (mostly my hockey team). Since I haven't used oatmeal before I wanted to make sure I had the science down pat before jeopardizing my reputation
I now have to decide on a small amount of base malt to use in the steeping so it won't impact the final stout. I have a feeling it doesn't really matter.