All of the indoor races I've done (not many, 10-15) had great traction. I found that I actually did better starting in 1st gear. It is usually short enough that you can run first gear all the way to the first turn.
Starts mean a lot because passing can be difficult and the races are usually short.
Make sure nothing is leaking from your bike...they get really picky about that indoors.
The atmosphere at those kinds of races is not as family oriented as normal outdoor races and you'll need to be more careful about leaving stuff laying around with no one to watch it.
Given riders of similar abilities, the big area that will make the difference in lap times is usually how well you can get through the whoops. That will be where you pass people without them blocking you.