I think you're doing yourself a disservice if you don't plan on using a good rub and injection on the brisket. While it may be your first comp, it won't be the first for everyone else, and I'd wager that the vast majority of your competitors will be using more than salt and pepper on their brisket. Plus, it only takes a few minutes to inject at a contest anyways, just build that into your timeline.
As far as the bark on the butt, I noticed the same problem with my Backwoods vs. the UDS. I think it's a moisture thing.