Level loading/transition and gameplay workflow

Does anyone have any suggestions / experience on how to go about building out the level workflow for a complete game using the platformer kit / torqueX? Below is a description of the workflow that I am looking to implement (everything under the Start Game branch is what I am looking for guidance for):

- Developer Splash Screen (completed)
- Engine Splash Screen (completed)
- Main Menu (completed)
    - Start Game
        - Launches the first level in a stage
            (stage consists of 4 levels - .txscene files)
            (user could be starting on an advanced stage so this needs to be dynamic, not always stage 1)
        - As each level is passed there is a brief summary screen then onto next level
            (would like to have all the level data for each level in the stage pre-loaded so this transition is short)
        - Once the final level in the stage is completed there is a stage summary screen that totals scores, etc.
            (would like to load the next stage data during this summary screen)
    - Options (completed)
    - Help (completed)
    - Quit (completed)

The key elements I am looking for a solution for are when and how to load the stage data without impacting the user (for the Start Game action the user will probably need to get a loading screen since we don't know what stage they will be starting on, background loading during stage completed screen since we will know what stage is next at this point, etc).