A spell cast using jump-start will always be exiled afterward, whether it resolves, it's countered, or it leaves the stack in some other way
In a game, the token you create can absolutely stand in as long as it is a helpful aid to the game
For those who are interested in typal synergies, Grand Duke, Advisor to the King is the card for you
Help your players qualify for these by encouraging them to do soor if they don't yet have a Wizards Account, invite them to register for one at These Prerelease rewards require registration with a Wizards Account: Collectible crystal counters : give one d10 spindown die to Prerelease players with each event (while supplies last)
We've also tried to include cards you might actually run into or be able to purchase yourself, avoiding the most expensive MTG cards, stuff on the Reserved List that most players can't possibly afford