Slow down? Are you kidding me? I speed up to get it over with.
Get over it, champ. You had a bad day. It happens. Move on, don't dwell.
Ditch the pace obsession, focus on consistent mileage and strength training, and your economy will improve naturally.
Duh, of course you need poop bags. That's not even a question. As for pace, if the dog can't keep up, maybe you're not running fast enough. Just kidding, sorta. I've run with my pup a few times, and it's all about training them to heel. Get that down, and you're golden.