I just finished bottling this kit. I let it sit in the primary for 2 weeks, and then in a secondary for 3 weeks (with 2 cups of dark-toasted oak chips). The FG was higher than anticipated--1.027. In hindsight, I should have left it in the secondary with an electric warmer for another week, just to ensure a full fermentation. Also, I only used a single packet of dry nottingham yeast--two would have likely been ideal, based on the OG.
But, I bottled it anyways, since I'm going to Alaska for the next 2 months. IMO, a bit of unfermented carbs/sugars add a lot to a beer's flavor complexity, while the ABV suffers only slightly. This beer's going to sit in bottles for another 6-8 weeks. The beer's been bottled for merely a week, but the carbonation's already going on strong, based on what I've seen in my one "tester" PET bottle.
MrGneissGuy, I'd absolutely recommend that you follow through with your ambitions of spice additions. Stouts are all about flavor complexity. Imperial Stouts are the most forgiving beers around when it comes to that--adding lactose and spices will just make the taste and aroma bigger and better, without compromising the dark, malty fundamentals of the varietal.
AFAIK, stouts are all about making your tongue's tastebuds explode in at least 7 different directions.
You can't lose, with this kit.