A few things:
Oats (malted or flaked) need to be mashed, not just steeped. Malted oats do contain the enzymes needed to convert starches to sugars, but you have to hold them with the right amount of water (1-2 qrts/lb) at the right temperature (~150) for the right amount of time (45+ minutes) to make it work.
Otherwise it looks like a solid recipe to me.
I would aim lower for carbonation, a big rich stout doesn't need as much carbonation as many other styles, low carbonation will make it seem creamier. I'd suggest using a priming calculator that takes the temperature and actual volume of beer into account.
Vanilla extract is very delicate, I'd add it to taste at bottling (or toss a split vanilla bean into the wort after fermentation ends).
I would give it a few weeks in secondary to clarify and make sure fermentation is complete.