The DLH will be a little hectic that weekend. The expo is held there on Friday and Saturday so there will be a lot of people in and out of the hotel getting their race stuff. As for race morning, it most likely will be loud. The staging area and finish line are in the parking lot of the hotel. The race will be on DL Drive right at the monorail and DTD pverpass.
Saturday morning is the 5k and in the past has started at the Mickey parking lot. It goes off at 6:45 and they have a dj that starts around 6 am. Not sure if you can hear though. They haven't announced the course yet, but you might hear the start and music if it's in the same place.
Sunday will be a lot louder for you. The dj starts around 4:30 or so and goes until about 5:30. The race starts at 5:45 and in the past there have been some small fireworks. You might also hear the announcers and starts or each of the waves. It should be a little quiet until 6:45/7 when the elite runner comes and you'll hear the announcers again. The runners will then start coming through and be running until about 9:30 or so. The finish of the course goes through the service road so getting into the park in the morning will take a little bit of time. The hold people until there is a clear space in the course before allowing you to cross over to DTD.
The parks won't be crazy busy, but they'll be somewhat busy. The waits will be about 15-20 min to 45 min depending on the rides. Indy and Peter Pan will be the 45 waits and HM and POTC will be the 15-20 min to give you an idea. TSMM will be about an 45-hour. But w/ Cars Land opening, maybe everyone will be in DCA so DL won't be as busy.