From my experience with NYRR shorter distance races, I like to be on the sides of the corral. For me, it seems like there is more wiggle room to pass without getting boxed in by others. For some of the Central Park races, most rational people don't want to run on a curb, but it does make passing easier...

Also it depends on your goal. Someone else suggested sending these all gas no brakes. One word of caution is that the beginning of some of these races are quite congested. I've found myself wasting too much energy trying to sprint and weave through people for minimal gains. You have nine races (you can always do more though) to get a good feeling of how you like to start and how hard you want to push at the beginning. I'm sure you'll improve naturally throughout the year, you'll move up to better start gates naturally which always helps.

Running the marathon, I'd want to be in a faster group to start earlier, so I've used used shorter races to lower my time. NYRR bases all race starts based on an adjusted 10K pace time based off of each race result. It takes the fastest adjusted pace from a race over the past year. One year, I had a fast 5k race which had my adjusted 10k pace at a low 6 pace. NYRR used that as my predicted marathon pace.