Indoor tris have several different formats, none of which I've done.  I don't see a problem flip turning though.  500m in 9 minutes is a 1:48/pace.  I think that would put you ahead of most people.  Check to see how they start it.  I assume its some kind of wave system, I've seen some where they seed people according to speed.  I would assume you circle swim?  In any case at 1:48/100m, I don't think you really have much to worry about