[Suicide Junkie]

2) Can a game be constructed where you run 100-200 turns, advancing one race while holding all of the others back and then open it up to other players?

If you just want that race to progress through the tech tree really fast, use a mod with all tech costs set to ONE research point.
At 12 techs per turn, you'll be done in no time, and then its just a matter of building the ships and moving them to where you want them to start.

Reset the rules back to normal, and run a turn to complete the process, then distribute the game to the players.

Having a copy of the components in a racial tech area will allow you to make the ships too, but the players won't be able to deconstruct and analyse them.